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Author |
Kocabas, T.; Cakir, D.; Gulseren, O.; Ay, F.; Perkgoz, N.K.; Sevik, C. |
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Title |
A distinct correlation between the vibrational and thermal transport properties of group VA monolayer crystals |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Nanoscale |
Abbreviated Journal |
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Volume |
10 |
Issue |
16 |
Pages |
7803-7812 |
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Keywords  |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
The investigation of thermal transport properties of novel two-dimensional materials is crucially important in order to assess their potential to be used in future technological applications, such as thermoelectric power generation. In this respect, the lattice thermal transport properties of the monolayer structures of group VA elements (P, As, Sb, Bi, PAs, PSb, PBi, AsSb, AsBi, SbBi, P3As1, P3Sb1, P1As3, and As3Sb1) with a black phosphorus like puckered structure were systematically investigated by first-principles calculations and an iterative solution of the phonon Boltzmann transport equation. Phosphorene was found to have the highest lattice thermal conductivity, , due to its low average atomic mass and strong interatomic bonding character. As a matter of course, anisotropic was obtained for all the considered materials, owing to anisotropy in frequency values and phonon group velocities calculated for these structures. However, the determined linear correlation between the anisotropy in the values of P, As, and Sb is significant. The results corresponding to the studied compound structures clearly point out that thermal (electronic) conductivity of pristine monolayers might be suppressed (improved) by alloying them with the same group elements. For instance, the room temperature of PBi along the armchair direction was predicted to be as low as 1.5 W m(-1) K-1, whereas that of P was predicted to be 21 W m(-1) K-1. In spite of the apparent differences in structural and vibrational properties, we peculiarly revealed an intriguing correlation between the values of all the considered materials as = c(1) + c(2)/m(2), in particular along the zigzag direction. Furthermore, our calculations on compound structures clearly showed that the thermoelectric potential of these materials can be improved by suppressing their thermal properties. The presence of ultra-low values and high electrical conductivity (especially along the armchair direction) makes this class of monolayers promising candidates for thermoelectric applications. |
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Wos |
000431030000054 |
Publication Date |
2018-03-22 |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2040-3364; 2040-3372 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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no |
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Call Number |
UA @ admin @ c:irua:193785 |
Serial |
7388 |
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Author |
Yorulmaz, U.; Demiroglu, I.; Cakir, D.; Gulseren, O.; Sevik, C. |
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Title |
A systematicalab-initioreview of promising 2D MXene monolayers towards Li-ion battery applications |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
JPhys Energy |
Abbreviated Journal |
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Volume |
2 |
Issue |
3 |
Pages |
032006 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Two-dimensional materials have been attracting increasing interests because of their outstanding properties for Lithium-ion battery applications. In particular, a material family called MXenes (Mn+1Cn, where n = 1, 2, 3) have been recently attracted immense interest in this respect due to their incomparable fast-charging properties and high capacity promises. In this article, we review the state-of-the-art computational progress on Li-ion battery applications of MXene materials in accordance with our systematical DFT calculations. Structural, mechanical, dynamical, and electrical properties of 20 distinct MXene (M: Sc, Ti, V, Cr, Nb, Mo, Hf, Ta, W, and Zr) have been discussed. The battery performances of these MXene monolayers are further investigated by Li-ion binding energies, open circuit voltage values, and Li migration energy barriers. The experimental and theoretical progress up to date demonstrates particularly the potential of non-terminated or pristine MXene materials in Li ion-storage applications. Stability analyses show most of the pristine MXenes should be achievable, however susceptible to the development progress on the experimental growth procedures. Among pristine MXenes, Ti2C, V2C, Sc2C, and Zr2C compounds excel with their high charge/discharge rate prospect due to their extremely low Li diffusion energy barriers. Considering also their higher predicted gravimetric capacities, Sc, Ti, V, and Zr containing MXenes are more promising for their utilization in energy storage applications. |
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Wos |
000569868600001 |
Publication Date |
2020-07-16 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2515-7655 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.9 |
Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: 6.9; 2020 IF: NA |
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Call Number |
UA @ admin @ c:irua:193748 |
Serial |
7399 |
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Author |
Siriwardane, E.M.D.; Demiroglu, I.; Sevik, C.; Cakir, D. |
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Title |
Achieving Fast Kinetics and Enhanced Li Storage Capacity for Ti3C2O2 by Intercalation of Quinone Molecules |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
ACS applied energy materials |
Abbreviated Journal |
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Volume |
2 |
Issue |
2 |
Pages |
1251-1258 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Using first-principles calculations, we demonstrated that high lithium storage capacity and fast kinetics are achieved for Ti3C2O2 by preintercalating organic molecules. As a proof-of-concept, two different quinone molecules, namely 1,4-benzoquinone (C6H4O2) and tetrafluoro-1,4-benzoquinone (C6F4O2) were selected as the molecular linkers to demonstrate the feasibility of this interlayer engineering strategy for energy storage. As compared to Ti3C2O2 bilayer without linker molecules, our pillared structures facilitate a much faster ion transport, promising a higher charge/discharge rate for Li. For example, while the diffusion barrier of a single Li ion within pristine Ti3C2O2 bilayer is at least 1.0 eV, it becomes 0.3 eV in pillared structures, which is comparable and even lower than that of commercial materials. At high Li concentrations, the calculated diffusion barriers are as low as 0.4 eV. Out-of-plane migration of Li ions is hindered due to large barrier energy with a value of around 1-1.35 eV. Concerning storage capacity, we can only intercalate one monolayer of Li within pristine Ti3C2O2 bilayer. In contrast, pillared structures offer significantly higher storage capacity. Our calculations showed that at least two layers of Li can be intercalated between Ti3C2O2 layers without forming bulk Li and losing the pillared structure upon Li loading/unloading. A small change in the in-plane lattice parameters (<0.5%) and volume (<1.0%) and ab initio molecular dynamics simulations prove the stability of the pillared structures against Li intercalation and thermal effects. Intercalated molecules avoid the large contraction/expansion of the whole structure, which is one of the key problems in electrochemical energy storage. Pillared structures allow us to realize electrodes with high capacity and fast kinetics. Our results open new research paths for improving the performance of not only MXenes but also other layered materials for supercapacitor and battery applications. |
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Wos |
000459948900037 |
Publication Date |
2019-01-04 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2574-0962 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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no |
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Call Number |
UA @ admin @ c:irua:193759 |
Serial |
7414 |
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Author |
Scolfaro, D.; Finamor, M.; Trinchao, L.O.; Rosa, B.L.T.; Chaves, A.; Santos, P., V.; Iikawa, F.; Couto, O.D.D., Jr. |
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Title |
Acoustically driven stark effect in transition metal dichalcogenide monolayers |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Acs Nano |
Abbreviated Journal |
Acs Nano |
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Volume |
15 |
Issue |
9 |
Pages |
15371-15380 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
The Stark effect is one of the most efficient mechanisms to manipulate many-body states in nanostructured systems. In mono- and few-layer transition metal dichalcogenides, it has been successfully induced by optical and electric field means. Here, we tune the optical emission energies and dissociate excitonic states in MoSe2 monolayers employing the 220 MHz in-plane piezoelectric field carried by surface acoustic waves. We transfer the monolayers to high dielectric constant piezoelectric substrates, where the neutral exciton binding energy is reduced, allowing us to efficiently quench (above 90%) and red-shift the excitonic optical emissions. A model for the acoustically induced Stark effect yields neutral exciton and trion in-plane polarizabilities of 530 and 630 x 10(-5) meV/(kV/cm)(2), respectively, which are considerably larger than those reported for monolayers encapsulated in hexagonal boron nitride. Large in-plane polarizabilities are an attractive ingredient to manipulate and modulate multiexciton interactions in two-dimensional semiconductor nanostructures for optoelectronic applications. |
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Corporate Author |
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Wos |
000703553600129 |
Publication Date |
2021-08-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1936-0851 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
13.942 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 13.942 |
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Call Number |
UA @ admin @ c:irua:182545 |
Serial |
7415 |
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Author |
Zhang, G.; Huang, S.; Chaves, A.; Yan, H. |
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Title |
Black phosphorus as tunable Van der Waals quantum wells with high optical quality |
Type |
A1 Journal article |
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Year |
2023 |
Publication |
ACS nano |
Abbreviated Journal |
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Volume |
17 |
Issue |
6 |
Pages |
6073-6080 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Van der Waals quantum wells, naturally formed in two-dimensional layered materials with nanoscale thickness, possess many inherent advantages over conventional molecular beam epitaxy grown counterparts, and could bring up intriguing physics and applications. However, optical transitions originated from the series of quantized states in these emerging quantum wells are still elusive. Here, we show that multilayer black phosphorus appears to be an excellent candidate for van der Waals quantum wells with well-defined subbands and high optical quality. Using infrared absorption spectroscopy, we probe subband structures of multilayer black phosphorus with tens of atomic layers, revealing clear signatures for optical transitions with subband index as high as 10, far from what was attainable previously. Surprisingly, in addition to allowed transitions, an unexpected series of “forbidden” transitions is also evidently observed, which enables us to determine energy spacings separately for conduction and valence subbands. Furthermore, the linear tunability of subband spacings by temperature and strain is demonstrated. Our results are expected to facilitate potential applications for infrared optoelectronics based on tunable van der Waals quantum wells. |
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Corporate Author |
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Place of Publication |
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Wos |
000953463300001 |
Publication Date |
2023-03-13 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1936-0851 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
17.1 |
Times cited |
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Open Access |
Not_Open_Access |
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Notes |
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Approved |
Most recent IF: 17.1; 2023 IF: 13.942 |
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Call Number |
UA @ admin @ c:irua:196100 |
Serial |
7565 |
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Author |
Lee, Y.; Forte, J.D.'arf S.; Chaves, A.; Kumar, A.; Tran, T.T.; Kim, Y.; Roy, S.; Taniguchi, T.; Watanabe, K.; Chernikov, A.; Jang, J.I.; Low, T.; Kim, J. |
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Title |
Boosting quantum yields in two-dimensional semiconductors via proximal metal plates |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Nature Communications |
Abbreviated Journal |
Nat Commun |
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Volume |
12 |
Issue |
1 |
Pages |
7095 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
The short exciton lifetime and strong exciton-exciton interaction in transition metal dichalcogenides limit the efficiency of exciton emission. Here, the authors show that exciton-exciton interaction in monolayer WS2 can be screened using proximal metal plates, leading to an improved quantum yield. Monolayer transition metal dichalcogenides (1L-TMDs) have tremendous potential as atomically thin, direct bandgap semiconductors that can be used as convenient building blocks for quantum photonic devices. However, the short exciton lifetime due to the defect traps and the strong exciton-exciton interaction in TMDs has significantly limited the efficiency of exciton emission from this class of materials. Here, we show that exciton-exciton interaction in 1L-WS2 can be effectively screened using an ultra-flat Au film substrate separated by multilayers of hexagonal boron nitride. Under this geometry, induced dipolar exciton-exciton interaction becomes quadrupole-quadrupole interaction because of effective image dipoles formed within the metal. The suppressed exciton-exciton interaction leads to a significantly improved quantum yield by an order of magnitude, which is also accompanied by a reduction in the exciton-exciton annihilation (EEA) rate, as confirmed by time-resolved optical measurements. A theoretical model accounting for the screening of the dipole-dipole interaction is in a good agreement with the dependence of EEA on exciton densities. Our results suggest that fundamental EEA processes in the TMD can be engineered through proximal metallic screening, which represents a practical approach towards high-efficiency 2D light emitters. |
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Wos |
000728559600014 |
Publication Date |
2021-12-07 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2041-1723 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
12.124 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 12.124 |
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Call Number |
UA @ admin @ c:irua:184870 |
Serial |
7566 |
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Author |
Demiroglu, I.; Karaaslan, Y.; Kocabas, T.; Keceli, M.; Vazquez-Mayagoitia, A.; Sevik, C. |
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Title |
Computation of the thermal expansion coefficient of graphene with Gaussian approximation potentials |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Journal Of Physical Chemistry C |
Abbreviated Journal |
J Phys Chem C |
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Volume |
125 |
Issue |
26 |
Pages |
14409-14415 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Direct experimental measurement of thermal expansion coefficient without substrate effects is a challenging task for two-dimensional (2D) materials, and its accurate estimation with large-scale ab initio molecular dynamics is computationally very expensive. Machine learning-based interatomic potentials trained with ab initio data have been successfully used in molecular dynamics simulations to decrease the computational cost without compromising the accuracy. In this study, we investigated using Gaussian approximation potentials to reproduce the density functional theory-level accuracy for graphene within both lattice dynamical and molecular dynamical methods, and to extend their applicability to larger length and time scales. Two such potentials are considered, GAP17 and GAP20. GAP17, which was trained with pristine graphene structures, is found to give closer results to density functional theory calculations at different scales. Further vibrational and structural analyses verify that the same conclusions can be deduced with density functional theory level in terms of the reasoning of the thermal expansion behavior, and the negative thermal expansion behavior is associated with long-range out-of-plane phonon vibrations. Thus, it is argued that the enabled larger system sizes by machine learning potentials may even enhance the accuracy compared to small-size-limited ab initio molecular dynamics. |
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Place of Publication |
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Wos |
000672734100027 |
Publication Date |
2021-06-24 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1932-7447; 1932-7455 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.536 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 4.536 |
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Call Number |
UA @ admin @ c:irua:179850 |
Serial |
7719 |
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Author |
Doevenspeck, J.; Zografos, O.; Gurunarayanan, S.; Lauwereins, R.; Raghavan, P.; Sorée, B. |
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Title |
Design and simulation of plasmonic interference-based majority gate |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
AIP advances |
Abbreviated Journal |
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Volume |
7 |
Issue |
6 |
Pages |
065116 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Major obstacles in current CMOS technology, such as the interconnect bottleneck and thermal heat management, can be overcome by employing subwavelength-scaled light in plasmonic waveguides and devices. In this work, a plasmonic structure that implements the majority (MAJ) gate function is designed and thoroughly studied through simulations. The structure consists of three merging waveguides, serving as the MAJ gate inputs. The information of the logic signals is encoded in the phase of transmitted surface plasmon polaritons (SPP). SPPs are excited at all three inputs and the phase of the output SPP is determined by theMAJof the input phases. The operating dimensions are identified and the functionality is verified for all input combinations. This is the first reported simulation of a plasmonic MAJ gate and thus contributes to the field of optical computing at the nanoscale. (C) 2017 Author(s). |
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Place of Publication |
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Wos |
000404621200036 |
Publication Date |
2017-06-23 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2158-3226 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:152632 |
Serial |
7764 |
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Author |
Kocabas, T.; Ozden, A.; Demiroglu, I.; Cakir, D.; Sevik, C. |
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Title |
Determination of Dynamically Stable Electrenes toward Ultrafast Charging Battery Applications |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
The journal of physical chemistry letters |
Abbreviated Journal |
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Volume |
9 |
Issue |
15 |
Pages |
4267-4274 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Electrenes, an atomically thin form of layered electrides, are very recent members of the 2D materials family. In this work, we employed first principle calculations to determine stable, exfoliatable, and application-promising 2D electrene materials among possible M2X compounds, where M is a group II-A metal and X is a nonmetal element (C, N, P, As, and Sb). The promise of stable electrene compounds for battery applications is assessed via their exfoliation energy, adsorption properties, and migration energy barriers toward relevant Li, Na, K, and Ca atoms. Our calculations revealed five new stable electrene candidates in addition to previously known Ca2N and Sr2N. Among these seven dynamically stable electrenes, Ba2As, Ba2P, Ba2Sb, Ca2N, Sr2N, and Sr2P are found to be very promising for either K or Na ion batteries due to their extremely low migration energy barriers (5-16 meV), which roughly demonstrates 105 times higher mobility than graphene and two to four times higher mobility than other promising 2D materials such as MXene (Mo2C). |
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Corporate Author |
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Publisher |
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Place of Publication |
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Language |
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Wos |
000440956500020 |
Publication Date |
2018-07-11 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1948-7185 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:193765 |
Serial |
7779 |
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Author |
Gjerding, M.N.; Cavalcante, L.S.R.; Chaves, A.; Thygesen, K.S. |
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Title |
Efficient Ab initio modeling of dielectric screening in 2D van der Waals materials : including phonons, substrates, and doping |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Journal Of Physical Chemistry C |
Abbreviated Journal |
J Phys Chem C |
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Volume |
124 |
Issue |
21 |
Pages |
11609-11616 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
The quantum electrostatic heterostructure (QEH) model allows for efficient computation of the dielectric screening properties of layered van der Waals (vdW)-bonded heterostructures in terms of the dielectric functions of the individual two-dimensional (2D) layers. Here, we extend the QEH model by including (1) contributions to the dielectric function from infrared active phonons in the 2D layers, (2) screening from homogeneous bulk substrates, and (3) intraband screening from free carriers in doped 2D semiconductor layers. We demonstrate the potential of the extended QEH model by calculating the dispersion of coupled phonons in multilayer stacks of hexagonal boron-nitride (hBN), the strong hybridization of plasmons and optical phonons in graphene/hBN heterostructures, the effect of substrate screening on the exciton series of monolayer MoS2, and the properties of hyperbolic plasmons in a doped phosphorene sheet. The new QEH code is distributed as a Python package with a simple command line interface and a comprehensive library of dielectric building blocks for the most common 2D materials, providing an efficient open platform for dielectric modeling of realistic vdW heterostructures. |
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Corporate Author |
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Place of Publication |
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Language |
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Wos |
000614615900022 |
Publication Date |
2020-05-04 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
|
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1932-7447; 1932-7455 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.7 |
Times cited |
|
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 3.7; 2020 IF: 4.536 |
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| |
Call Number |
UA @ admin @ c:irua:176187 |
Serial |
7852 |
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| Permanent link to this record |
| |
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| |
|
Author |
Sarikurt, S.; Kocabas, T.; Sevik, C. |
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| |
Title |
High-throughput computational screening of 2D materials for thermoelectrics |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Journal Of Materials Chemistry A |
Abbreviated Journal |
J Mater Chem A |
|
| |
Volume |
8 |
Issue |
37 |
Pages |
19674-19683 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
High-performance thermoelectric materials are critical in recuperating the thermal losses in various machinery and promising in renewable energy applications. In this respect, the search for novel thermoelectric materials has attracted considerable attention. In particular, low dimensional materials have been proposed as potential candidates due to their unique and controllable thermal and electronic transport properties. The considerable potential of several two-dimensional materials as thermoelectric devices has already been uncovered and many new candidates that merit further research have been suggested. In this regard, we comprehensively investigate the thermoelectric coefficients and electronic fitness function (EFF) of a large family of structurally isotropic and anisotropic two-dimensional layered materials using density functional theory combined with semi-classical Boltzmann transport theory. With this high-throughput screening, we bring to light additional 2D crystals that haven't been previously classified as favorable TE materials. We predict that Pb2Se2, GeS2, As-2, NiS2, Hf2O6, Zr2O6, AsBrS, ISbTe, ISbSe, AsISe, and AsITe are promising isotropic thermoelectric materials due to their considerably high EFF values. In addition to these materials, Hf2Br4, Zr2Br4, Hf2Cl4, Zr2Cl4, Hf2O6, Zr(2)O(6)and Os(2)O(4)exhibit strong anisotropy and possess prominently high EFF values. |
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Address |
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Corporate Author |
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Thesis |
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| |
Publisher |
|
Place of Publication |
|
Editor |
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| |
Language |
|
Wos |
000573889000046 |
Publication Date |
2020-08-31 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2050-7488; 2050-7496 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
11.9 |
Times cited |
|
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 11.9; 2020 IF: 8.867 |
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| |
Call Number |
UA @ admin @ c:irua:193778 |
Serial |
8039 |
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| Permanent link to this record |
| |
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| |
|
Author |
Korkmaz, Y.A.; Bulutay, C.; Sevik, C. |
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| |
Title |
k · p parametrization and linear and circular dichroism in strained monolayer (Janus) transition metal dichalcogenides from first-principles |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Journal Of Physical Chemistry C |
Abbreviated Journal |
J Phys Chem C |
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| |
Volume |
125 |
Issue |
13 |
Pages |
7439-7450 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
Semiconductor monolayer transition metal dichalcogenides (TMDs) have brought a new paradigm by introducing optically addressable valley degree of freedom. Concomitantly, their high flexibility constitutes a unique platform that links optics to mechanics via valleytronics. With the intention to expedite the research in this direction, we investigated ten TMDs, namely MoS2, MoSe2, MoTe2, WS2, WSe2, WTe2, MoSSe, MoSeTe, WSSe, and WSeTe, which particularly includes their so-called janus types (JTMDs). First, we obtained their electronic band structures using regular and hybrid density functional theory (DFT) calculations in the presence of the spin-orbit coupling and biaxial or uniaxial strain. Our DFT results indicated that against the expectations based on their reported piezoelectric behavior, JTMDs typically interpolated between the standard band properties of the constituent TMDs without producing a novel feature. Next, by fitting to our DFT data we generated both spinless and spinful k center dot p parameter sets which are quite accurate over the K valley where the optical activity occurs. As an important application of this parametrization, we considered the circular and linear dichroism under strain. Among the studied (J)TMDs, WTe2 stood out with its largest linear dichroism under uniaxial strain because of its narrower band gap and large K valley uniaxial deformation potential. This led us to suggest WTe2 monolayer membranes for optical polarization-based strain measurements, or conversely, as strain tunable optical polarizers. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
|
Wos |
000639044400045 |
Publication Date |
2021-03-26 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1932-7447; 1932-7455 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.536 |
Times cited |
|
Open Access |
OpenAccess |
|
| |
Notes |
|
Approved |
Most recent IF: 4.536 |
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| |
Call Number |
UA @ admin @ c:irua:178264 |
Serial |
8136 |
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| Permanent link to this record |
| |
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| |
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Author |
Wang, F.; Wang, C.; Chaves, A.; Song, C.; Zhang, G.; Huang, S.; Lei, Y.; Xing, Q.; Mu, L.; Xie, Y.; Yan, H. |
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| |
Title |
Prediction of hyperbolic exciton-polaritons in monolayer black phosphorus |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Nature Communications |
Abbreviated Journal |
Nat Commun |
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| |
Volume |
12 |
Issue |
1 |
Pages |
5628 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
Hyperbolic polaritons exhibit large photonic density of states and can be collimated in certain propagation directions. The majority of hyperbolic polaritons are sustained in man-made metamaterials. However, natural-occurring hyperbolic materials also exist. Particularly, natural in-plane hyperbolic polaritons in layered materials have been demonstrated in MoO3 and WTe2, which are based on phonon and plasmon resonances respectively. Here, by determining the anisotropic optical conductivity (dielectric function) through optical spectroscopy, we predict that monolayer black phosphorus naturally hosts hyperbolic exciton-polaritons due to the pronounced in-plane anisotropy and strong exciton resonances. We simultaneously observe a strong and sharp ground state exciton peak and weaker excited states in high quality monolayer samples in the reflection spectrum, which enables us to determine the exciton binding energy of similar to 452 meV. Our work provides another appealing platform for the in-plane natural hyperbolic polaritons, which is based on excitons rather than phonons or plasmons. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
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Wos |
000698984500003 |
Publication Date |
2021-10-12 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
12.124 |
Times cited |
|
Open Access |
Not_Open_Access |
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| |
Notes |
|
Approved |
Most recent IF: 12.124 |
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| |
Call Number |
UA @ admin @ c:irua:191688 |
Serial |
8404 |
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| Permanent link to this record |
| |
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| |
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Author |
Sarikurt, S.; Çakir, D.; Keceli, M.; Sevik, C. |
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Title |
The influence of surface functionalization on thermal transport and thermoelectric properties of MXene monolayers |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Nanoscale |
Abbreviated Journal |
|
|
| |
Volume |
10 |
Issue |
18 |
Pages |
8859-8868 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
The newest members of a two-dimensional material family, involving transition metal carbides and nitrides (called MXenes), have garnered increasing attention due to their tunable electronic and thermal properties depending on the chemical composition and functionalization. This flexibility can be exploited to fabricate efficient electrochemical energy storage (batteries) and energy conversion (thermoelectric) devices. In this study, we calculated the Seebeck coefficients and lattice thermal conductivity values of oxygen terminated M2CO2 (where M = Ti, Zr, Hf, Sc) monolayer MXene crystals in two different functionalization configurations (model-II (MD-II) and model-III (MD-III)), using density functional theory and Boltzmann transport theory. We estimated the thermoelectric figure-of-merit, zT, of these materials by two different approaches, as well. First of all, we found that the structural model (i.e. adsorption site of oxygen atom on the surface of MXene) has a paramount impact on the electronic and thermoelectric properties of MXene crystals, which can be exploited to engineer the thermoelectric properties of these materials. The lattice thermal conductivity kappa(l), Seebeck coefficient and zT values may vary by 40% depending on the structural model. The MD-III configuration always has the larger band gap, Seebeck coefficient and zT, and smaller kappa(l) as compared to the MD-II structure due to a larger band gap, highly flat valence band and reduced crystal symmetry in the former. The MD-III configuration of Ti2CO2 and Zr2CO2 has the lowest kappa(l) as compared to the same configuration of Hf2CO2 and Sc2CO2. Among all the considered structures, the MD-II configuration of Hf2CO2 has the highest kappa(l), and Ti2CO2 and Zr2CO2 in the MD-III configuration have the lowest kappa(l). For instance, while the band gap of the MD-II configuration of Ti2CO2 is 0.26 eV, it becomes 0.69 eV in MD-III. The zT(max) value may reach up to 1.1 depending on the structural model of MXene. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
|
Wos |
000432096400055 |
Publication Date |
2018-04-06 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
2040-3364; 2040-3372 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
|
Times cited |
|
Open Access |
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| |
Notes |
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Approved |
no |
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| |
Call Number |
UA @ admin @ c:irua:193788 |
Serial |
8654 |
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| Permanent link to this record |
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Author |
Espinosa, I.M.P.; Karaaslan, Y.; Sevik, C.; Martini, A. |
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Title |
Atomistic model of the anisotropic response of ortho-Mo₂C to indentation |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
AIP advances |
Abbreviated Journal |
|
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| |
Volume |
13 |
Issue |
6 |
Pages |
065125-65127 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
Molybdenum carbide has various applications for which studying the material using classical molecular dynamics simulations would be valuable. Here, we develop an empirical potential within the Tersoff formalism using particle swarm optimization for the orthorhombic phase of Mo2C. The developed potential is shown to predict lattice constants, elastic properties, and equation of state results that are consistent with current and previously reported results from experiments and first principles calculations. We demonstrate the potential with simulations of indentation using multiple indenter sizes that load and unload in three different directions relative to the crystallographic lattice of orthorhombic Mo2C. Direction-dependent force-displacement trends are analyzed and explained in terms of the spatial distributions of stress and strain within the material during indentation. This study reveals the anisotropic elasticity of orthorhombic Mo2C and, more generally, provides researchers with a new empirical potential that can be used to explore the properties and behavior of the material going forward. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
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Wos |
001016472500005 |
Publication Date |
2023-06-23 |
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| |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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| |
Series Volume |
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Series Issue |
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Edition |
|
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| |
ISSN |
2158-3226 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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| |
Impact Factor |
|
Times cited |
|
Open Access |
OpenAccess |
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| |
Notes |
|
Approved |
Most recent IF: NA |
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| |
Call Number |
UA @ admin @ c:irua:198333 |
Serial |
8834 |
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| Permanent link to this record |
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| |
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Author |
Kocabas, T.; Keceli, M.; Vazquez-Mayagoitia, A.; Sevik, C. |
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Title |
Gaussian approximation potentials for accurate thermal properties of two-dimensional materials |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Nanoscale |
Abbreviated Journal |
|
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| |
Volume |
15 |
Issue |
19 |
Pages |
8772-8780 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
Two-dimensional materials (2DMs) continue to attract a lot of attention, particularly for their extreme flexibility and superior thermal properties. Molecular dynamics simulations are among the most powerful methods for computing these properties, but their reliability depends on the accuracy of interatomic interactions. While first principles approaches provide the most accurate description of interatomic forces, they are computationally expensive. In contrast, classical force fields are computationally efficient, but have limited accuracy in interatomic force description. Machine learning interatomic potentials, such as Gaussian Approximation Potentials, trained on density functional theory (DFT) calculations offer a compromise by providing both accurate estimation and computational efficiency. In this work, we present a systematic procedure to develop Gaussian approximation potentials for selected 2DMs, graphene, buckled silicene, and h-XN (X = B, Al, and Ga, as binary compounds) structures. We validate our approach through calculations that require various levels of accuracy in interatomic interactions. The calculated phonon dispersion curves and lattice thermal conductivity, obtained through harmonic and anharmonic force constants (including fourth order) are in excellent agreement with DFT results. HIPHIVE calculations, in which the generated GAP potentials were used to compute higher-order force constants instead of DFT, demonstrated the first-principles level accuracy of the potentials for interatomic force description. Molecular dynamics simulations based on phonon density of states calculations, which agree closely with DFT-based calculations, also show the success of the generated potentials in high-temperature simulations. |
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Address |
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Corporate Author |
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Thesis |
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| |
Publisher |
|
Place of Publication |
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Editor |
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| |
Language |
|
Wos |
000976615200001 |
Publication Date |
2023-04-19 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2040-3364; 2040-3372 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
6.7 |
Times cited |
|
Open Access |
Not_Open_Access |
|
| |
Notes |
|
Approved |
Most recent IF: 6.7; 2023 IF: 7.367 |
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| |
Call Number |
UA @ admin @ c:irua:196722 |
Serial |
8873 |
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| Permanent link to this record |
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Author |
Sevik, C.; Bekaert, J.; Milošević, M.V. |
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Title |
Superconductivity in functionalized niobium-carbide MXenes |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Nanoscale |
Abbreviated Journal |
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| |
Volume |
15 |
Issue |
19 |
Pages |
8792-8799 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
We detail the effects of Cl and S functionalization on the superconducting properties of layered (bulk) and monolayer niobium carbide (Nb2C) MXene crystals, based on first-principles calculations combined with Eliashberg theory. For bulk layered Nb2CCl2, the calculated superconducting transition temperature (T-c) is in very good agreement with the recently measured value of 6 K. We show that T-c is enhanced to 10 K for monolayer Nb2CCl2, due to an increase in the density of states at the Fermi level, and the corresponding electron-phonon coupling. We further demonstrate feasible gate- and strain-induced enhancements of T-c for both bulk-layered and monolayer Nb2CCl2 crystals, resulting in T-c values of around 38 K. In the S-functionalized Nb2CCl2 crystals, our calculations reveal the importance of phonon softening in understanding their superconducting properties. Finally, we predict that Nb3C2S2 in bulk-layered and monolayer forms is also superconducting, with a T-c of around 28 K. Considering that Nb2C is not superconducting in pristine form, our findings promote functionalization as a pathway towards robust superconductivity in MXenes. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
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Wos |
000976973900001 |
Publication Date |
2023-04-11 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
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Series Issue |
|
Edition |
|
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| |
ISSN |
2040-3364; 2040-3372 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
6.7 |
Times cited |
|
Open Access |
OpenAccess |
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| |
Notes |
|
Approved |
Most recent IF: 6.7; 2023 IF: 7.367 |
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| |
Call Number |
UA @ admin @ c:irua:196711 |
Serial |
8938 |
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| Permanent link to this record |
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Author |
Mazzola, F.; Hassani, H.; Amoroso, D.; Chaluvadi, S.K.; Fujii, J.; Polewczyk, V.; Rajak, P.; Koegler, M.; Ciancio, R.; Partoens, B.; Rossi, G.; Vobornik, I.; Ghosez, P.; Orgiani, P. |
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| |
Title |
Unveiling the electronic structure of pseudotetragonal WO₃ thin films |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
The journal of physical chemistry letters |
Abbreviated Journal |
|
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| |
Volume |
14 |
Issue |
32 |
Pages |
7208-7214 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
WO3 isa 5d compound that undergoes severalstructuraltransitions in its bulk form. Its versatility is well-documented,with a wide range of applications, such as flexopiezoelectricity,electrochromism, gating-induced phase transitions, and its abilityto improve the performance of Li-based batteries. The synthesis ofWO(3) thin films holds promise in stabilizing electronicphases for practical applications. However, despite its potential,the electronic structure of this material remains experimentally unexplored.Furthermore, its thermal instability limits its use in certain technologicaldevices. Here, we employ tensile strain to stabilize WO3 thin films, which we call the pseudotetragonal phase, and investigateits electronic structure using a combination of photoelectron spectroscopyand density functional theory calculations. This study reveals theFermiology of the system, notably identifying significant energy splittingsbetween different orbital manifolds arising from atomic distortions.These splittings, along with the system's thermal stability,offer a potential avenue for controlling inter- and intraband scatteringfor electronic applications. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
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Wos |
001044522400001 |
Publication Date |
2023-08-08 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
1948-7185 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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| |
Impact Factor |
5.7 |
Times cited |
|
Open Access |
OpenAccess |
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| |
Notes |
|
Approved |
Most recent IF: 5.7; 2023 IF: 9.353 |
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| |
Call Number |
UA @ admin @ c:irua:198391 |
Serial |
8951 |
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| Permanent link to this record |
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Author |
Huang, S.; Griffin, E.; Cai, J.; Xin, B.; Tong, J.; Fu, Y.; Kravets, V.; Peeters, F.M.; Lozada-Hidalgo, M. |
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Title |
Gate-controlled suppression of light-driven proton transport through graphene electrodes |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Nature communications |
Abbreviated Journal |
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| |
Volume |
14 |
Issue |
1 |
Pages |
6932-6937 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Recent experiments demonstrated that proton transport through graphene electrodes can be accelerated by over an order of magnitude with low intensity illumination. Here we show that this photo-effect can be suppressed for a tuneable fraction of the infra-red spectrum by applying a voltage bias. Using photocurrent measurements and Raman spectroscopy, we show that such fraction can be selected by tuning the Fermi energy of electrons in graphene with a bias, a phenomenon controlled by Pauli blocking of photo-excited electrons. These findings demonstrate a dependence between graphene's electronic and proton transport properties and provide fundamental insights into molecularly thin electrode-electrolyte interfaces and their interaction with light. Recent experiments have shown that proton transport through graphene electrodes can be promoted by light, but the understanding of this phenomenon remains unclear. Here, the authors report the electrical tunability of this photo-effect, showing a connection between graphene electronic and proton transport properties. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
|
Editor |
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| |
Language |
|
Wos |
001094448600003 |
Publication Date |
2023-10-31 |
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Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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| |
Impact Factor |
16.6 |
Times cited |
|
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 16.6; 2023 IF: 12.124 |
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| |
Call Number |
UA @ admin @ c:irua:201185 |
Serial |
9041 |
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| Permanent link to this record |
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Author |
Xiang, F.; Gupta, A.; Chaves, A.; Krix, Z.E.; Watanabe, K.; Taniguchi, T.; Fuhrer, M.S.; Peeters, F.M.; Neilson, D.; Milošević, M.V.; Hamilton, A.R. |
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Title |
Intra-zero-energy Landau level crossings in bilayer graphene at high electric fields |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Nano letters |
Abbreviated Journal |
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| |
Volume |
23 |
Issue |
21 |
Pages |
9683-9689 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
The highly tunable band structure of the zero-energy Landau level (zLL) of bilayer graphene makes it an ideal platform for engineering novel quantum states. However, the zero-energy Landau level at high electric fields has remained largely unexplored. Here we present magnetotransport measurements of bilayer graphene in high transverse electric fields. We observe previously undetected Landau level crossings at filling factors nu = -2, 1, and 3 at high electric fields. These crossings provide constraints for theoretical models of the zero-energy Landau level and show that the orbital, valley, and spin character of the quantum Hall states at high electric fields is very different from low electric fields. At high E, new transitions between states at nu = -2 with different orbital and spin polarization can be controlled by the gate bias, while the transitions between nu = 0 -> 1 and nu = 2 -> 3 show anomalous behavior. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
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Wos |
001102148900001 |
Publication Date |
2023-10-26 |
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| |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1530-6984 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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| |
Impact Factor |
10.8 |
Times cited |
|
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 10.8; 2023 IF: 12.712 |
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| |
Call Number |
UA @ admin @ c:irua:201200 |
Serial |
9052 |
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| Permanent link to this record |
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| |
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Author |
Wahab, O.J.; Daviddi, E.; Xin, B.; Sun, P.Z.; Griffin, E.; Colburn, A.W.; Barry, D.; Yagmurcukardes, M.; Peeters, F.M.; Geim, A.K.; Lozada-Hidalgo, M.; Unwin, P.R. |
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| |
Title |
Proton transport through nanoscale corrugations in two-dimensional crystals |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Nature |
Abbreviated Journal |
|
|
| |
Volume |
620 |
Issue |
7975 |
Pages |
1-17 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
Defect-free graphene is impermeable to all atoms(1-5) and ions(6,7) under ambient conditions. Experiments that can resolve gas flows of a few atoms per hour through micrometre-sized membranes found that monocrystalline graphene is completely impermeable to helium, the smallest atom(2,5). Such membranes were also shown to be impermeable to all ions, including the smallest one, lithium(6,7). By contrast, graphene was reported to be highly permeable to protons, nuclei of hydrogen atoms(8,9). There is no consensus, however, either on the mechanism behind the unexpectedly high proton permeability(10-14) or even on whether it requires defects in graphene's crystal lattice(6,8,15-17). Here, using high-resolution scanning electrochemical cell microscopy, we show that, although proton permeation through mechanically exfoliated monolayers of graphene and hexagonal boron nitride cannot be attributed to any structural defects, nanoscale non-flatness of two-dimensional membranes greatly facilitates proton transport. The spatial distribution of proton currents visualized by scanning electrochemical cell microscopy reveals marked inhomogeneities that are strongly correlated with nanoscale wrinkles and other features where strain is accumulated. Our results highlight nanoscale morphology as an important parameter enabling proton transport through two-dimensional crystals, mostly considered and modelled as flat, and indicate that strain and curvature can be used as additional degrees of freedom to control the proton permeability of two-dimensional materials. A study using high-resolution scanning electrochemical cell microscopy attributes proton permeation through defect-free graphene and hexagonal boron nitride to transport across areas of the structure that are under strain. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
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Wos |
001153630400007 |
Publication Date |
2023-08-23 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
0028-0836; 1476-4687 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
64.8 |
Times cited |
|
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 64.8; 2023 IF: 40.137 |
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| |
Call Number |
UA @ admin @ c:irua:203827 |
Serial |
9078 |
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| Permanent link to this record |
| |
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| |
|
Author |
Tran, T.T.; Lee, Y.; Roy, S.; Tran, T.U.; Kim, Y.; Taniguchi, T.; Watanabe, K.; Milošević, M.V.; Lim, S.C.; Chaves, A.; Jang, J.I.; Kim, J. |
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| |
Title |
Synergetic enhancement of quantum yield and exciton lifetime of monolayer WS₂ by proximal metal plate and negative electric bias |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
ACS nano |
Abbreviated Journal |
|
|
| |
Volume |
18 |
Issue |
1 |
Pages |
220-228 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
The efficiency of light emission is a critical performance factor for monolayer transition metal dichalcogenides (1L-TMDs) for photonic applications. While various methods have been studied to compensate for lattice defects to improve the quantum yield (QY) of 1L-TMDs, exciton-exciton annihilation (EEA) is still a major nonradiative decay channel for excitons at high exciton densities. Here, we demonstrate that the combined use of a proximal Au plate and a negative electric gate bias (NEGB) for 1L-WS2 provides a dramatic enhancement of the exciton lifetime at high exciton densities with the corresponding QY enhanced by 30 times and the EEA rate constant decreased by 80 times. The suppression of EEA by NEGB is attributed to the reduction of the defect-assisted EEA process, which we also explain with our theoretical model. Our results provide a synergetic solution to cope with EEA to realize high-intensity 2D light emitters using TMDs. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
|
Wos |
001139516800001 |
Publication Date |
2023-12-21 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1936-0851 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
|
| |
Impact Factor |
17.1 |
Times cited |
|
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 17.1; 2023 IF: 13.942 |
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| |
Call Number |
UA @ admin @ c:irua:202811 |
Serial |
9101 |
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| Permanent link to this record |
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| |
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Author |
Vermeulen, B.B.; Raymenants, E.; Pham, V.T.; Pizzini, S.; Sorée, B.; Wostyn, K.; Couet, S.; Nguyen, V.D.; Temst, K. |
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Title |
Towards fully electrically controlled domain-wall logic |
Type |
A1 Journal article |
| |
Year |
2024 |
Publication |
AIP advances |
Abbreviated Journal |
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|
| |
Volume |
14 |
Issue |
2 |
Pages |
025030-25035 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
Utilizing magnetic tunnel junctions (MTJs) for write/read and fast spin-orbit-torque (SOT)-driven domain-wall (DW) motion for propagation, enables non-volatile logic and majority operations, representing a breakthrough in the implementation of nanoscale DW logic devices. Recently, current-driven DW logic gates have been demonstrated via magnetic imaging, where the Dzyaloshinskii-Moriya interaction (DMI) induces chiral coupling between perpendicular magnetic anisotropy (PMA) regions via an in-plane (IP) oriented region. However, full electrical operation of nanoscale DW logic requires electrical write/read operations and a method to pattern PMA and IP regions compatible with the fabrication of PMA MTJs. Here, we study the use of a Hybrid Free Layer (HFL) concept to combine an MTJ stack with DW motion materials, and He+ ion irradiation to convert the stack from PMA to IP. First, we investigate the free layer thickness dependence of 100-nm diameter HFL-MTJ devices and find an optimal CoFeB thickness, from 7 to 10 angstrom, providing high tunneling magnetoresistance (TMR) readout and efficient spin-transfer torque (STT) writing. We then show that high DMI materials, like Pt/Co, can be integrated into an MTJ stack via interlayer exchange coupling with the CoFeB free layer. In this design, DMI values suitable for SOT-driven DW motion are measured by asymmetric bubble expansion. Finally, we demonstrate that He+ irradiation reliably converts the coupled free layers from PMA to IP. These findings offer a path toward the integration of fully electrically controlled DW logic circuits. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
001163573400005 |
Publication Date |
2024-02-16 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
2158-3226 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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| |
Impact Factor |
|
Times cited |
|
Open Access |
Not_Open_Access |
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| |
Notes |
|
Approved |
Most recent IF: NA |
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| |
Call Number |
UA @ admin @ c:irua:203823 |
Serial |
9109 |
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| Permanent link to this record |
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Author |
Tiwari, S.; Van de Put, M.; Sorée, B.; Hinkle, C.; Vandenberghe, W.G. |
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Title |
Reduction of magnetic interaction due to clustering in doped transition-metal dichalcogenides : a case study of Mn-, V-, and Fe-doped WSe₂ |
Type |
A1 Journal article |
| |
Year |
2024 |
Publication |
ACS applied materials and interfaces |
Abbreviated Journal |
|
|
| |
Volume |
16 |
Issue |
4 |
Pages |
4991-4998 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
Using Hubbard-U-corrected density functional theory calculations, lattice Monte Carlo simulations, and spin Monte Carlo simulations, we investigate the impact of dopant clustering on the magnetic properties of WSe2 doped with period four transition metals. We use manganese (Mn) and iron (Fe) as candidate n-type dopants and vanadium (V) as the candidate p-type dopant, substituting the tungsten (W) atom in WSe2. Specifically, we determine the strength of the exchange interaction in Fe-, Mn-, and V-doped WSe2 in the presence of clustering. We show that the clusters of dopants are energetically more stable than discretely doped systems. Further, we show that in the presence of dopant clustering, the magnetic exchange interaction significantly reduces because the magnetic order in clustered WSe2 becomes more itinerant. Finally, we show that the clustering of the dopant atoms has a detrimental effect on the magnetic interaction, and to obtain an optimal Curie temperature, it is important to control the distribution of the dopant atoms. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
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Wos |
001155511900001 |
Publication Date |
2024-01-18 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1944-8244 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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| |
Impact Factor |
9.5 |
Times cited |
|
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 9.5; 2024 IF: 7.504 |
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| |
Call Number |
UA @ admin @ c:irua:203830 |
Serial |
9169 |
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| Permanent link to this record |
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Author |
Sethu, K.K.V.; Yasin, F.; Swerts, J.; Sorée, B.; De Boeck, J.; Kar, G.S.; Garello, K.; Couet, S. |
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| |
Title |
Spin-orbit torque vector quantification in nanoscale magnetic tunnel junctions |
Type |
A1 Journal article |
| |
Year |
2024 |
Publication |
ACS nano |
Abbreviated Journal |
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| |
Volume |
18 |
Issue |
21 |
Pages |
13506-13516 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
Spin-orbit torques (SOT) allow ultrafast, energy-efficient toggling of magnetization state by an in-plane charge current for applications such as magnetic random-access memory (SOT-MRAM). Tailoring the SOT vector comprising of antidamping (T-AD) and fieldlike (T-FL) torques could lead to faster, more reliable, and low-power SOT-MRAM. Here, we establish a method to quantify the longitudinal (T-AD) and transverse (T-FL) components of the SOT vector and its efficiency chi(AD) and chi(FL), respectively, in nanoscale three-terminal SOT magnetic tunnel junctions (SOT-MTJ). Modulation of nucleation or switching field (B-SF) for magnetization reversal by SOT effective fields (B-SOT) leads to the modification of SOT-MTJ hysteresis loop behavior from which chi(AD) and chi(FL) are quantified. Surprisingly, in nanoscale W/CoFeB SOT-MTJ, we find chi(FL) to be (i) twice as large as chi(AD) and (ii) 6 times as large as chi(FL) in micrometer-sized W/CoFeB Hall-bar devices. Our quantification is supported by micromagnetic and macrospin simulations which reproduce experimental SOT-MTJ Stoner-Wohlfarth astroid behavior only for chi(FL) > chi(AD). Additionally, from the threshold current for current-induced magnetization switching with a transverse magnetic field, we show that in SOT-MTJ, T-FL plays a more prominent role in magnetization dynamics than T-AD. Due to SOT-MRAM geometry and nanodimensionality, the potential role of nonlocal spin Hall spin current accumulated adjacent to the SOT-MTJ in the mediation of T-FL and chi(FL) amplification merits to be explored. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
|
Wos |
001226121700001 |
Publication Date |
2024-05-15 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
1936-0851 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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| |
Impact Factor |
17.1 |
Times cited |
|
Open Access |
|
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| |
Notes |
|
Approved |
Most recent IF: 17.1; 2024 IF: 13.942 |
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Call Number |
UA @ admin @ c:irua:205980 |
Serial |
9173 |
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| Permanent link to this record |
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| |
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Author |
Li, C.; Lyu, Y.-Y.; Yue, W.-C.; Huang, P.; Li, H.; Li, T.; Wang, C.-G.; Yuan, Z.; Dong, Y.; Ma, X.; Tu, X.; Tao, T.; Dong, S.; He, L.; Jia, X.; Sun, G.; Kang, L.; Wang, H.; Peeters, F.M.; Milošević, M.V.; Wu, P.; Wang, Y.-L. |
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Title |
Unconventional superconducting diode effects via antisymmetry and antisymmetry breaking |
Type |
A1 Journal article |
| |
Year |
2024 |
Publication |
Nano letters |
Abbreviated Journal |
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| |
Volume |
24 |
Issue |
14 |
Pages |
4108-4116 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
Symmetry breaking plays a pivotal role in unlocking intriguing properties and functionalities in material systems. For example, the breaking of spatial and temporal symmetries leads to a fascinating phenomenon: the superconducting diode effect. However, generating and precisely controlling the superconducting diode effect pose significant challenges. Here, we take a novel route with the deliberate manipulation of magnetic charge potentials to realize unconventional superconducting flux-quantum diode effects. We achieve this through suitably tailored nanoengineered arrays of nanobar magnets on top of a superconducting thin film. We demonstrate the vital roles of inversion antisymmetry and its breaking in evoking unconventional superconducting effects, namely a magnetically symmetric diode effect and an odd-parity magnetotransport effect. These effects are nonvolatilely controllable through in situ magnetization switching of the nanobar magnets. Our findings promote the use of antisymmetry (breaking) for initiating unconventional superconducting properties, paving the way for exciting prospects and innovative functionalities in superconducting electronics. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
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Wos |
001193010700001 |
Publication Date |
2024-03-27 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1530-6984 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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| |
Impact Factor |
10.8 |
Times cited |
|
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 10.8; 2024 IF: 12.712 |
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| |
Call Number |
UA @ admin @ c:irua:205553 |
Serial |
9180 |
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| Permanent link to this record |
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Author |
da Costa, L.F.; de Barros, A.G.; de Figueiredo Lopes Lucena, L.C.; de Figueiredo Lopes Lucena, A.E. |
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Title |
Asphalt mixture reinforced with banana fibres |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Road Materials And Pavement Design |
Abbreviated Journal |
Road Mater Pavement |
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Volume |
|
Issue |
|
Pages |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT); Energy and Materials in Infrastructure and Buildings (EMIB) |
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| |
Abstract |
Stone Matrix Asphalt (SMA) is a gap-graded mixture which requires high contents of asphalt binder. To prevent draindown, natural or synthetic fibres and polymer-modified asphalt binders are conventionally used in SMA. Banana agribusiness is one of the major sources of post-harvest residue in Brazil. Amongst those residues, fibres extracted from the pseudostem of the banana plant are resistant and used in diverse purposes. The present study assesses the incorporation of fibres from the pseudostem of the banana plant in an SMA mixture. The fibre contents and lengths capable to prevent binder draindown were evaluated from draindown tests. Mechanical properties of an SMA mixture stabilised with different banana fibre lengths were analysed through the tests of Marshall stability, modified Lottman, Indirect Tensile Strength and Cantabro. The results indicated that the fibres studied are a viable alternative for SMA, stabilising draindown and improving its mechanical performance, especially at the length of 20 mm. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
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Wos |
000508499900001 |
Publication Date |
2020-01-22 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
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| |
ISSN |
1468-0629; 2164-7402 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.7 |
Times cited |
|
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: 3.7; 2020 IF: 1.401 |
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| |
Call Number |
UA @ admin @ c:irua:178727 |
Serial |
7495 |
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| Permanent link to this record |
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Author |
Ferreira da Costa, L.; de Lucena, L.C.F.L.; de Lucena, A.E.F.L.; Grangeiro de Barros, A. |
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Title |
Use of Banana Fibers in SMA Mixtures |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Journal Of Materials In Civil Engineering |
Abbreviated Journal |
J Mater Civil Eng |
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| |
Volume |
32 |
Issue |
1 |
Pages |
04019341 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT); Energy and Materials in Infrastructure and Buildings (EMIB) |
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| |
Abstract |
Asphalt binder draindown is a potential issue related to stone matrix asphalt (SMA) mixtures. One convenient approach for reducing binder drainage is the use of fibers as stabilizing additives. This study assesses the feasibility of incorporating fibers from banana plants into an SMA mixture as a proposed use for residues from banana cultivation. We found the fiber content capable of preventing draindown and subsequently evaluated the influence of fiber length on the mechanical properties of an SMA mixture. Samples were prepared in a Superpave gyratory compactor with four different fiber lengths (5, 10, 15, and 20 mm) at a fixed content (0.3% by weight) and then compared to samples without fibers. Indirect tensile strength, resilient and dynamic modulus, flow number, and fatigue life tests were conducted. Overall, fibers improved the mechanical properties analyzed. These enhancements were more pronounced for the samples with 15- and 20-mm fibers. Thus, a smaller number of longer fibers was more beneficial to the fiber reinforcement of mixtures than a larger number of shorter fibers. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
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Editor |
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| |
Language |
|
Wos |
000497709300014 |
Publication Date |
2019-11-13 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
0899-1561 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.2 |
Times cited |
|
Open Access |
|
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| |
Notes |
|
Approved |
Most recent IF: 3.2; 2020 IF: 1.644 |
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| |
Call Number |
UA @ admin @ c:irua:178728 |
Serial |
8719 |
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| Permanent link to this record |
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Author |
Frolov, A.S.; Sanchez-Barriga, J.; Callaert, C.; Hadermann, J.; Fedorov, A., V; Usachov, D.Y.; Chaika, A.N.; Walls, B.C.; Zhussupbekov, K.; Shvets, I., V.; Muntwiler, M.; Amati, M.; Gregoratti, L.; Varykhalov, A.Y.; Rader, O.; Yashina, L., V. |
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Title |
Atomic and electronic structure of a multidomain GeTe crystal |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Acs Nano |
Abbreviated Journal |
Acs Nano |
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| |
Volume |
14 |
Issue |
12 |
Pages |
16576-16589 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
Renewed interest in the ferroelectric semi-conductor germanium telluride was recently triggered by the direct observation of a giant Rashba effect and a 30-year-old dream about a functional spin field-effect transistor. In this respect, all-electrical control of the spin texture in this material in combination with ferroelectric properties at the nanoscale would create advanced functionalities in spintronics and data information processing. Here, we investigate the atomic and electronic properties of GeTe bulk single crystals and their (111) surfaces. We succeeded in growing crystals possessing solely inversion domains of similar to 10 nm thickness parallel to each other. Using HAADF-TEM we observe two types of domain boundaries, one of them being similar in structure to the van der Waals gap in layered materials. This structure is responsible for the formation of surface domains with preferential Te-termination (similar to 68%) as we determined using photoelectron diffraction and XPS. The lateral dimensions of the surface domains are in the range of similar to 10-100 nm, and both Ge- and Te-terminations reveal no reconstruction. Using spin-ARPES we establish an intrinsic quantitative relationship between the spin polarization of pure bulk states and the relative contribution of different terminations, a result that is consistent with a reversal of the spin texture of the bulk Rashba bands for opposite configurations of the ferroelectric polarization within individual nanodomains. Our findings are important for potential applications of ferroelectric Rashba semiconductors in nonvolatile spintronic devices with advanced memory and computing capabilities at the nanoscale. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
|
Wos |
000603308800022 |
Publication Date |
2020-11-02 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1936-0851 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
17.1 |
Times cited |
|
Open Access |
OpenAccess |
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| |
Notes |
|
Approved |
Most recent IF: 17.1; 2020 IF: 13.942 |
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| |
Call Number |
UA @ admin @ c:irua:175027 |
Serial |
6716 |
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| Permanent link to this record |
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Author |
Ding, L.; Zhao, L.; Weng, Y.; Schryvers, D.; Liu, Q.; Idrissi, H. |
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Title |
Atomic-scale investigation of the heterogeneous precipitation in the E (Al₁₈Mg₃Cr₂) dispersoid of 7075 aluminum alloy |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Journal Of Alloys And Compounds |
Abbreviated Journal |
J Alloy Compd |
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Volume |
851 |
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156890 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
The heterogeneous precipitation of the eta (MgZn2) phase on the E (Al18Mg3Cr2) dispersoids of the 7075 aluminum alloy was systematically investigated by atomic resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and energy dispersive X-ray spectrometry (EDX). It is found that coarse B particles are heterogeneously precipitated at the E particle interface after water quenching and isothermal aging at 120 degrees C. The incoherent E/Al interface is responsible for the high tendency of heterogeneous precipitation of the B phase. Two different orientation relationships (ORs) between the eta, E and Al matrix are identified: OR1 [2 (11) over bar0](eta)[011](E)//[(1) over bar 12](Al), (01 (1) over bar0)(eta)//(13 (3) over bar)(E)//(201)(Al), OR2 [(1) over bar 12](E)//[0001](eta)//[011](Al), (01 (1) over bar0 )(eta)//(220)(E)//(34 (4) over bar)(Al). The eta phase is preferential to nucleate along the {111}(E) or the {220}(E) planes, depending on its OR. The heterogeneous nucleation of B phase on the E particle could stabilize the E/Al interface by introducing a coherent E/eta interface, which increases the drive force of heterogeneous precipitation. The reorientation of eta phase and mutual diffusion of solute atoms could assist the coherency of the E/eta interface. The present results suggest that increasing the coherency of the E/Al interface is a promising method to suppress the heterogeneous precipitation of the eta phase. (C) 2020 Elsevier B.V. All rights reserved. |
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Wos |
000579868900103 |
Publication Date |
2020-08-25 |
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ISSN |
0925-8388 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.133 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 3.133 |
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Call Number |
UA @ admin @ c:irua:173503 |
Serial |
6717 |
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| Permanent link to this record |
