| Records |
| Author |
Jiang, J.; Milošević, M.V.; Wang, Y.-L.; Xiao, Z.-L.; Peeters, F.M.; Chen, Q.-H. |
| Title |
Field-free superconducting diode in a magnetically nanostructured superconductor |
Type |
A1 Journal article |
Year  |
2022 |
Publication |
Physical review applied |
Abbreviated Journal |
Phys Rev Appl |
| Volume |
18 |
Issue |
3 |
Pages |
034064-34069 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
A strong superconducting diode effect (SDE) is revealed in a thin superconducting film periodically nanostructured with magnetic dots. The SDE is caused by the current-activated dissipation mitigated by vortex-antivortex pairs (VAPs), which periodically nucleate under the dots, move and annihilate in the superconductor-eventually driving the system to the high-resistive state. Inversing the polarity of the applied current destimulates the nucleation of VAPs, the system remains superconducting up to far larger currents, leading to the pronounced diodic response. Our dissipative Ginzburg-Landau simulations detail the involved processes, and provide reliable geometric and parametric ranges for the experimental realiza-tion of such a nonvolatile superconducting diode, which operates in the absence of any applied magnetic field while being fluxonic by design. |
| 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 |
000870234200001 |
Publication Date |
2022-09-23 |
| 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 |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.6 |
Times cited |
2 |
Open Access |
OpenAccess |
| Notes |
|
Approved |
Most recent IF: 4.6 |
| Call Number |
UA @ admin @ c:irua:191539 |
Serial |
7307 |
| Permanent link to this record |
| |
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| |
| Author |
Sethu, K.K.V.; Ghosh, S.; Couet, S.; Swerts, J.; Sorée, B.; De Boeck, J.; Kar, G.S.; Garello, K. |
| Title |
Optimization of tungsten beta-phase window for spin-orbit-torque magnetic random-access memory |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Physical Review Applied |
Abbreviated Journal |
Phys Rev Appl |
| Volume |
16 |
Issue |
6 |
Pages |
064009 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Switching induced by spin-orbit torque (SOT) is being vigorously explored, as it allows the control of magnetization using an in-plane current, which enables a three-terminal magnetic-tunnel-junction geometry with isolated read and write paths. This significantly improves the device endurance and the read stability, and allows reliable subnanosecond switching. Tungsten in the beta phase, beta-W, has the largest reported antidamping SOT charge-to-spin conversion ratio (theta(AD) approximate to -60%) for heavy metals. However, beta-W has a limitation when one is aiming for reliable technology integration: the beta phase is limited to a thickness of a few nanometers and enters the alpha phase above 4 nm in our samples when industry-relevant deposition tools are used. Here, we report our approach to extending the range of beta-W, while simultaneously improving the SOT efficiency by introducing N and O doping of W. Resistivity and XRD measurements confirm the extension of the beta phase from 4 nm to more than 10 nm, and transport characterization shows an effective SOT efficiency larger than -44.4% (reaching approximately -60% for the bulk contribution). In addition, we demonstrate the possibility of controlling and enhancing the perpendicular magnetic anisotropy of a storage layer (Co-Fe-B). Further, we integrate the optimized W(O, N) into SOT magnetic random-access memory (SOT-MRAM) devices and project that, for the same thickness of SOT material, the switching current decreases by 25% in optimized W(O, N) compared with our standard W. Our results open the path to using and further optimizing W for integration of SOT-MRAM technology. |
| 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 |
000729005800002 |
Publication Date |
2021-12-03 |
| 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 |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.808 |
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 4.808 |
| Call Number |
UA @ admin @ c:irua:184832 |
Serial |
7007 |
| Permanent link to this record |
| |
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| |
| Author |
Tao, Z.H.; Dong, H.M.; Milošević, M.V.; Peeters, F.M.; Van Duppen, B. |
| Title |
Tailoring dirac plasmons via anisotropic dielectric environment by design |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Physical Review Applied |
Abbreviated Journal |
Phys Rev Appl |
| Volume |
16 |
Issue |
5 |
Pages |
054030 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Dirac plasmons in a two-dimensional (2D) crystal are strongly affected by the dielectric properties of the environment, due to interaction of their electric field lines with the surrounding medium. Using graphene as a 2D reservoir of free carriers, one can engineer a material configuration that provides an anisotropic environment to the plasmons. In this work, we discuss the physical properties of Dirac plasmons in graphene surrounded by an arbitrary anisotropic dielectric and exemplify how h-BN-based heterostructures can be designed to bear the required anisotropic characteristics. We calculate how dielec-tric anisotropy impacts the spatial propagation of the plasmons and find that an anisotropy-induced plasmon mode emerges, together with a damping pathway, that stem from the out-of-plane off-diagonal elements in the dielectric tensor. Furthermore, we find that one can create hyperbolic plasmons by inher-iting the dielectric hyperbolicity of the designed material environment. Strong control over plasmon propagation patterns can be realized in a similar manner. Finally, we show that in this way one can also control the polarization of the light-matter excitations that constitute the plasmon. Taken together, our results promote the design of the dielectric environment as an effective path to tailor the plasmonic response of graphene on the nanoscopic level. |
| 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 |
000720372500002 |
Publication Date |
2021-11-15 |
| 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 |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.808 |
Times cited |
1 |
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 4.808 |
| Call Number |
UA @ admin @ c:irua:184063 |
Serial |
7028 |
| Permanent link to this record |
| |
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| |
| Author |
Yin, L.; Juneja, R.; Lindsay, L.; Pandey, T.; Parker, D.S. |
| Title |
Semihard iron-based permanent-magnet materials |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Physical Review Applied |
Abbreviated Journal |
Phys Rev Appl |
| Volume |
15 |
Issue |
2 |
Pages |
024012 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Permanent magnets generally require a favorable, but difficult-to-achieve combination of high magnetization, Curie point, and magnetic anisotropy. Thus there have been few, if any, viable permanent magnets developed since the 1982 discovery of Nd2Fe14B [M. Sagawa, S. Fujimura, H. Yamamoto, Y. Matsuura, and S. Hirosawa, J. Appl. Phys. 57, 4094 (1985)]. Here we point out, both by direct first-principles calculations on the iron carbides and silicides Fe5C2, Fe5SiC, and Fe7C3 as well as a discussion of recent experimental findings, that there are numerous rare-earth-free iron-rich potential permanent-magnet materials with sufficient intrinsic magnetic properties to reasonably achieve room-temperature energy products of 20-25 MG Oe. This is substantially better than the performance of the best available rare-earth-free magnets based on ferrite, as well as shape-anisotropy-employing alnico. These magnets could plausibly fill, at low cost, the present performance “gap” [J. M. D. Coey, Scr. Mater. 67, 524 (2012)] between the best rare-earth-free magnets and rare-earth magnets such as Nd2Fe14B and Sm-Co. |
| 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 |
000614707800002 |
Publication Date |
2021-02-05 |
| 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 |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.808 |
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 4.808 |
| Call Number |
UA @ admin @ c:irua:176624 |
Serial |
6734 |
| Permanent link to this record |
| |
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| |
| Author |
Torsello, D.; Ummarino, G.A.; Bekaert, J.; Gozzelino, L.; Gerbaldo, R.; Tanatar, M.A.; Canfield, P.C.; Prozorov, R.; Ghigo, G. |
| Title |
Tuning the intrinsic anisotropy with disorder in the CaKFE₄As₄ superconductor |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physical Review Applied |
Abbreviated Journal |
Phys Rev Appl |
| Volume |
13 |
Issue |
6 |
Pages |
064046-64049 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We report on the anisotropy of the London penetration depth of CaKFe4As4, discussing how it relates to its electronic structure and how it modifies under introduction of disorder, both chemically induced (by Ni substitution) and irradiation induced (by 3.5-MeV protons). Indeed, CaKFe4As4 is particularly suitable for the study of fundamental superconducting properties due to its stoichiometric composition, exhibiting clean-limit behavior in the pristine samples and having a fairly high critical temperature, T-c approximate to 35 K. The London penetration depth lambda(L) is measured with a microwave-coplanar-resonator technique that allows us to deconvolve the anisotropic contributions lambda(L,ab) and lambda(L,c) and obtain the anisotropy parameter gamma(lambda) = lambda(L,c)/lambda(L,ab). The gamma(lambda) (T) found for the undoped pristine sample is in good agreement with previous literature and is here compared to ab initio density-functional-theory and Eliashberg calculations. The dependence of gamma(lambda) (T) on both chemical and irradiation-induced disorder is discussed to highlight which method is more suitable to decrease the direction dependence of the electromagnetic properties while maintaining a high critical temperature. Lastly, the relevance of an intrinsic anisotropy such as gamma(lambda) on application-related anisotropic parameters (critical current, pinning) is discussed in light of the recent employment of CaKFe4As4 in the production of wires. |
| 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 |
000540915800003 |
Publication Date |
2020-06-19 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.6 |
Times cited |
4 |
Open Access |
|
| Notes |
; This work was partially supported by the Italian Ministry of Education, University and Research (Project PRIN “HIBiSCUS,” Grant No. 201785KWLE). J.B. acknowledges the support of a postdoctoral fellowship of the Research Foundation-Flanders (FWO). The computational resources and services used for the first-principles calculations in this work were provided by the VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government-department EWI. Work done at Ames Laboratory was supported by the U.S. Department of Energy, Office of Basic Energy Science, Division of Materials Sciences and Engineering. Ames Laboratory is operated for the U.S. Department of Energy by Iowa State University under Contract No. DE-AC02-07CH11358. G.A.U. acknowledges support from the MEPhI Academic Excellence Project (Contract No. 702.a03.21.0005). ; |
Approved |
Most recent IF: 4.6; 2020 IF: 4.808 |
| Call Number |
UA @ admin @ c:irua:170178 |
Serial |
6641 |
| Permanent link to this record |
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| Author |
Karaaslan, Y.; Yapicioglu, H.; Sevik, C. |
| Title |
Assessment of Thermal Transport Properties of Group-III Nitrides: A Classical Molecular Dynamics Study with Transferable Tersoff-Type Interatomic Potentials |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physical Review Applied |
Abbreviated Journal |
Phys Rev Appl |
| Volume |
13 |
Issue |
3 |
Pages |
034027 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
In this study, by means of classical molecular dynamics simulations, we investigate the thermal-transport properties of hexagonal single-layer, zinc-blend, and wurtzite phases of BN, AlN, and GaN crystals, which are very promising for the application and design of high-quality electronic devices. With this in mind, we generate fully transferable Tersoff-type empirical interatomic potential parameter sets by utilizing an optimization procedure based on particle-swarm optimization. The predicted thermal properties as well as the structural, mechanical, and vibrational properties of all materials are in very good agreement with existing experimental and first-principles data. The impact of isotopes on thermal transport is also investigated and between approximately 10 and 50% reduction in phonon thermal transport with random isotope distribution is observed in BN and GaN crystals. Our investigation distinctly shows that the generated parameter sets are fully transferable and very useful in exploring the thermal properties of systems containing these nitrides. |
| 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 |
000518820200003 |
Publication Date |
2020-03-10 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.6 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 4.6; 2020 IF: 4.808 |
| Call Number |
UA @ admin @ c:irua:193766 |
Serial |
7508 |
| Permanent link to this record |
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| |
| Author |
de de Meux, A.J.; Pourtois, G.; Genoe, J.; Heremans, P. |
| Title |
Defects in amorphous semiconductors : the case of amorphous indium gallium zinc oxide |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Physical review applied |
Abbreviated Journal |
Phys Rev Appl |
| Volume |
9 |
Issue |
9 |
Pages |
054039 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
Based on a rational classification of defects in amorphous materials, we propose a simplified model to describe intrinsic defects and hydrogen impurities in amorphous indium gallium zinc oxide (a-IGZO). The proposed approach consists of organizing defects into two categories: point defects, generating structural anomalies such as metal-metal or oxygen-oxygen bonds, and defects emerging from changes in the material stoichiometry, such as vacancies and interstitial atoms. Based on first-principles simulations, it is argued that the defects originating from the second group always act as perfect donors or perfect acceptors. This classification simplifies and rationalizes the nature of defects in amorphous phases. In a-IGZO, the most important point defects are metal-metal bonds (or small metal clusters) and peroxides (O-O single bonds). Electrons are captured by metal-metal bonds and released by the formation of peroxides. The presence of hydrogen can lead to two additional types of defects: metal-hydrogen defects, acting as acceptors, and oxygen-hydrogen defects, acting as donors. The impact of these defects is linked to different instabilities observed in a-IGZO. Specifically, the diffusion of hydrogen and oxygen is connected to positive-and negative-bias stresses, while negative-bias illumination stress originates from the formation of peroxides. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
American Physical Society |
Place of Publication |
College Park, Md |
Editor |
|
| Language |
|
Wos |
000433070900003 |
Publication Date |
2018-05-25 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.808 |
Times cited |
7 |
Open Access |
OpenAccess |
| Notes |
|
Approved |
Most recent IF: 4.808 |
| Call Number |
UA @ lucian @ c:irua:151497 |
Serial |
5019 |
| Permanent link to this record |
| |
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| |
| Author |
Lu, A.K.A.; Houssa, M.; Luisier, M.; Pourtois, G. |
| Title |
Impact of layer alignment on the behavior of MoS2-ZrS2 tunnel field-effect transistors : an ab initio study |
Type |
A1 Journal article |
| Year |
2017 |
Publication |
Physical review applied |
Abbreviated Journal |
Phys Rev Appl |
| Volume |
8 |
Issue |
3 |
Pages |
034017 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
Tunnel field-effect transistors based on van der Waals heterostructures are emerging device concepts for low-power applications, auguring sub-60 mV/dec subthreshold swing values. In these devices, the channel is built from a stack of several different two-dimensional materials whose nature allows tailoring the band alignments and enables a good electrostatic control of the device. In this work, we propose a theoretical study of the variability of the performances of a MoS2-ZrS2 tunnel field-effect transistor induced by fluctuations of the relative position or the orientation of the layers. Our results indicate that although a steep subthreshold slope (20 mV/dec) is achievable, fluctuations in the relative orientation of the ZrS2 layer with respect to the MoS2 one lead to a significant variability in the tunneling current by about one decade. This arises from changes in the orbital overlap between the layers and from the modulation of the transport direction. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
American Physical Society |
Place of Publication |
College Park, Md |
Editor |
|
| Language |
|
Wos |
000411460400001 |
Publication Date |
2017-09-22 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.808 |
Times cited |
6 |
Open Access |
OpenAccess |
| Notes |
|
Approved |
Most recent IF: 4.808 |
| Call Number |
UA @ lucian @ c:irua:146741 |
Serial |
4785 |
| Permanent link to this record |
