| Records |
| Author |
Conti, S.; Van der Donck, M.; Perali, A.; Peeters, F.M.; Neilson, D. |
| Title |
Doping-dependent switch from one- to two-component superfluidity in coupled electron-hole van der Waals heterostructures |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
101 |
Issue |
22 |
Pages |
220504-220506 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The hunt for high-temperature superfluidity has received new impetus from the discovery of atomically thin stable materials. Electron-hole superfluidity in coupled MoSe2-WSe2 monolayers is investigated using a mean-field multiband model that includes band splitting caused by strong spin-orbit coupling. This splitting leads to a large energy misalignment of the electron and hole bands which is strongly modified by interchanging the doping of the monolayers. The choice of doping determines if the superfluidity is tunable from one to two components. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000538941900002 |
Publication Date |
2020-06-09 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.7 |
Times cited |
11 |
Open Access |
|
| Notes |
; This work was partially supported by the Fonds Wetenschappelijk Onderzoek (FWO-Vl), the Methusalem Foundation, and the FLAG-ERA project TRANS2DTMD. We thank A. R. Hamilton and A. Vargas-Paredes for useful discussions. ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
Call Number  |
UA @ admin @ c:irua:170201 |
Serial |
6489 |
| Permanent link to this record |
| |
|
| |
| Author |
Zhao, X.N.; Xu, W.; Xiao, Y.M.; Liu, J.; Van Duppen, B.; Peeters, F.M. |
| Title |
Terahertz optical Hall effect in monolayer MoS₂ in the presence of proximity-induced interactions |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
101 |
Issue |
24 |
Pages |
245412-12 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The effect of proximity-induced interactions such as Rashba spin-orbit coupling (SOC) and exchange interaction on the electronic and optical properties of n-type monolayer (ML) MoS2 is investigated. We predict and demonstrate that the Rashba SOC can induce an in-plane spin splitting with terahertz (THz) energy, while the exchange interaction lifts the energy degeneracy in different valleys. Thus, spin polarization can be achieved in an n-type ML MoS2 and valley Hall or optical Hall effect can be observed using linearly polarized THz radiation. In such a case, the transverse optical conductivity sigma(xy) (omega) results from spin-flip transition within spin-split conduction bands and from the fact that contributions from electrons with different spin orientations in different valleys can no longer be canceled out. Interestingly, we find that for fixed effective Zeeman field (or exchange interaction) the lowest spin-split conduction band in ML MoS2 can be tuned from one in the K valley to another one in the K' valley by varying the Rashba parameter lambda(R). Therefore, by changing lambda(R) we can turn the sign of the spin polarization and Im sigma(xy) (omega) from positive to negative. Moreover, we find that the dominant contribution of the selection rules to sigma(xx)(omega) is from electrons in the K valley and to sigma(xy) (omega) is from electrons in the K' valley. These important and interesting theoretical findings can be helpful to experimental observation of the optical Hall effect in valleytronic systems using linearly polarized THz radiation fields. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000538715500011 |
Publication Date |
2020-06-09 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.7 |
Times cited |
5 |
Open Access |
|
| Notes |
; This work was supported by the National Natural Science Foundation of China (Grants No. U1930116, No. U1832153, and No. 11574319) and the Center of Science and Technology of Hefei Academy of Science (Grant No. 2016FXZY002). ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
| Call Number |
UA @ admin @ c:irua:170206 |
Serial |
6622 |
| Permanent link to this record |
| |
|
| |
| Author |
Petrishcheva, E.; Tiede, L.; Schweinar, K.; Habler, G.; Li, C.; Gault, B.; Abart, R. |
| Title |
Spinodal decomposition in alkali feldspar studied by atom probe tomography |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physics And Chemistry Of Minerals |
Abbreviated Journal |
Phys Chem Miner |
| Volume |
47 |
Issue |
7 |
Pages |
Unsp 30 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
We used atom probe tomography to complement electron microscopy for the investigation of spinodal decomposition in alkali feldspar. To this end, gem-quality alkali feldspar of intermediate composition with a mole fraction of a(K) = 0.43 of the K end-member was prepared from Madagascar orthoclase by ion-exchange with (NaK)Cl molten salt. During subsequent annealing at 550 degrees C and close to ambient pressure the ion-exchanged orthoclase unmixed producing a coherent lamellar intergrowth of Na-rich and K-rich lamellae. The chemical separation was completed, and equilibrium Na-K partitioning between the different lamellae was attained within four days, which was followed by microstructural coarsening. After annealing for 4 days, the wavelength of the lamellar microstructure was approximate to 17 nm and it increased to approximate to 30 nm after annealing for 16 days. The observed equilibrium compositions of the Na-rich and K-rich lamellae are in reasonable agreement with an earlier experimental determination of the coherent solvus. The excess energy associated with compositional gradients at the lamellar interfaces was quantified from the initial wavelength of the lamellar microstructure and the lamellar compositions as obtained from atom probe tomography using the Cahn-Hilliard theory. The capability of atom probe tomography to deliver quantitative chemical compositions at nm resolution opens new perspectives for studying the early stages of exsolution. In particular, it helps to shed light on the phase relations in nm scaled coherent intergrowth. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000540150400001 |
Publication Date |
2020-06-07 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0342-1791 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.4 |
Times cited |
|
Open Access |
OpenAccess |
| Notes |
; Open access funding provided by Austrian Science Fund (FWF). This project was funded by the FWF Project P28238-N29. KS acknowledges IMPRS-SurMat for funding. Uwe Tezins, Andreas Sturm and Christian Bross are acknowledged for their support at the FIB & APT facilities at MPIE. We gratefully acknowledge the thorough and constructive reviews by Herbert Kroll and Luis Sanchez Munoz, who substantially contributed to improving an earlier version of the manuscript. ; |
Approved |
Most recent IF: 1.4; 2020 IF: 1.521 |
| Call Number |
UA @ admin @ c:irua:170208 |
Serial |
6611 |
| Permanent link to this record |
| |
|
| |
| Author |
Toso, S.; Akkerman, Q.A.; Martin-Garcia, B.; Prato, M.; Zito, J.; Infante, I.; Dang, Z.; Moliterni, A.; Giannini, C.; Bladt, E.; Lobato, I.; Ramade, J.; Bals, S.; Buha, J.; Spirito, D.; Mugnaioli, E.; Gemmi, M.; Manna, L. |
| Title |
Nanocrystals of lead chalcohalides : a series of kinetically trapped metastable nanostructures |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Journal Of The American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
| Volume |
142 |
Issue |
22 |
Pages |
10198-10211 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
We report the colloidal synthesis of a series of surfactant-stabilized lead chalcohalide nanocrystals. Our work is mainly focused on Pb4S3Br2, a chalcohalide phase unknown to date that does not belong to the ambient-pressure PbS-PbBr2 phase diagram. The Pb4S3Br2 nanocrystals herein feature a remarkably narrow size distribution (with a size dispersion as low as 5%), a good size tunability (from 7 to similar to 30 nm), an indirect bandgap, photoconductivity (responsivity = 4 +/- 1 mA/W), and stability for months in air. A crystal structure is proposed for this new material by combining the information from 3D electron diffraction and electron tomography of a single nanocrystal, X-ray powder diffraction, and density functional theory calculations. Such a structure is closely related to that of the recently discovered high-pressure chalcohalide Pb4S3I2 phase, and indeed we were able to extend our synthesis scheme to Pb4S3I2 colloidal nanocrystals, whose structure matches the one that has been published for the bulk. Finally, we could also prepare nanocrystals of Pb3S2Cl2, which proved to be a structural analogue of the recently reported bulk Pb3Se2Br2 phase. It is remarkable that one high-pressure structure (for Pb4S3I2) and two metastable structures that had not yet been reported (for Pb4S3Br2 and Pb3S2Cl2) can be prepared on the nanoscale by wet-chemical approaches. This highlights the important role of colloidal chemistry in the discovery of new materials and motivates further exploration into metal chalcohalide nanocrystals. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000538526500035 |
Publication Date |
2020-05-06 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0002-7863 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
15 |
Times cited |
32 |
Open Access |
OpenAccess |
| Notes |
; We would like to thank Dr. A. Toma for the access to the IIT clean room facilities' SEM/FIB and evaporators, the Smart Materials group (IIT) for the access to the ATR-FTIR equipment, S. Marras for the support during XRPD measurements, G. Pugliese for help with the TGA measurements, M. Campolucci for help with the experiments on NC growth kinetics, S. Lauciello for help with the SEM-EDX analyses, and D. Baranov and R. Brescia for the helpful discussions. We also acknowledge funding from the Programme for Research and Innovation Horizon 2020 (2014-2020) under the Marie Sklodowska-Curie Grant Agreement COMPASS No. 691185. I.I. acknowledges the Dutch NWO for financial support under the Vidi scheme (Grant No. 723.013.002). S.B. acknowledges support by means of the ERC Consolidator Grant No. 815128 REALNANO. E. M. and M.G acknowledge the Regione Toscana for funding the purchase of the Timepix detector through the FELIX project (Por CREO FESR 2014-2020 action). ; sygma |
Approved |
Most recent IF: 15; 2020 IF: 13.858 |
| Call Number |
UA @ admin @ c:irua:170218 |
Serial |
6566 |
| Permanent link to this record |
| |
|
| |
| Author |
Wozniak, T.; Faria, P.E., Jr.; Seifert, G.; Chaves, A.; Kunstmann, J. |
| Title |
Exciton g factors of van der Waals heterostructures from first-principles calculations |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
101 |
Issue |
23 |
Pages |
235408-235411 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
External fields are a powerful tool to probe optical excitations in a material. The linear energy shift of an excitation in a magnetic field is quantified by its effective g factor. Here we show how exciton g factors and their sign can be determined by converged first-principles calculations. We apply the method to monolayer excitons in semiconducting transition metal dichalcogenides and to interlayer excitons in MoSe2/WSe2 heterobilayers and obtain good agreement with recent experimental data. The precision of our method allows us to assign measured g factors of optical peaks to specific transitions in the band structure and also to specific regions of the samples. This revealed the nature of various, previously measured interlayer exciton peaks. We further show that, due to specific optical selection rules, g factors in van der Waals heterostructures are strongly spin and stacking-dependent. The calculation of orbital angular momenta requires the summation over hundreds of bands, indicating that for the considered two-dimensional materials the basis set size is a critical numerical issue. The presented approach can potentially be applied to a wide variety of semiconductors. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000537315100009 |
Publication Date |
2020-06-03 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9969; 2469-9950 |
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: 3.836 |
| Call Number |
UA @ admin @ c:irua:170219 |
Serial |
7944 |
| Permanent link to this record |
| |
|
| |
| Author |
McNaughton, B.; Milošević, M.V.; Perali, A.; Pilati, S. |
| Title |
Boosting Monte Carlo simulations of spin glasses using autoregressive neural networks |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physical Review E |
Abbreviated Journal |
Phys Rev E |
| Volume |
101 |
Issue |
5 |
Pages |
053312 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The autoregressive neural networks are emerging as a powerful computational tool to solve relevant problems in classical and quantum mechanics. One of their appealing functionalities is that, after they have learned a probability distribution from a dataset, they allow exact and efficient sampling of typical system configurations. Here we employ a neural autoregressive distribution estimator (NADE) to boost Markov chain Monte Carlo (MCMC) simulations of a paradigmatic classical model of spin-glass theory, namely, the two-dimensional Edwards-Anderson Hamiltonian. We show that a NADE can be trained to accurately mimic the Boltzmann distribution using unsupervised learning from system configurations generated using standard MCMC algorithms. The trained NADE is then employed as smart proposal distribution for the Metropolis-Hastings algorithm. This allows us to perform efficient MCMC simulations, which provide unbiased results even if the expectation value corresponding to the probability distribution learned by the NADE is not exact. Notably, we implement a sequential tempering procedure, whereby a NADE trained at a higher temperature is iteratively employed as proposal distribution in a MCMC simulation run at a slightly lower temperature. This allows one to efficiently simulate the spin-glass model even in the low-temperature regime, avoiding the divergent correlation times that plague MCMC simulations driven by local-update algorithms. Furthermore, we show that the NADE-driven simulations quickly sample ground-state configurations, paving the way to their future utilization to tackle binary optimization problems. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000535862000014 |
Publication Date |
2020-05-28 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1539-3755; 1550-2376 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.366 |
Times cited |
15 |
Open Access |
|
| Notes |
; The authors thank I. Murray, G. Carleo, and F. RicciTersenghi for useful discussions. Financial support from the FAR2018 project titled “Supervised machine learning for quantum matter and computational docking” of the University of Camerino and from the Italian MIUR under Project No. PRIN2017 CEnTraL 20172H2SC4 is gratefully acknowledged. S.P. also acknowledges the CINECA award under the ISCRA initiative, for the availability of high performance computing resources and support. M.V.M. gratefully acknowledges the Visiting Professorship program at the University of Camerino that facilitated the collaboration in this work. ; |
Approved |
Most recent IF: NA |
| Call Number |
UA @ admin @ c:irua:170244 |
Serial |
6463 |
| Permanent link to this record |
| |
|
| |
| Author |
Sun, C.; Liao, X.; Xia, F.; Zhao, Y.; Zhang, L.; Mu, S.; Shi, S.; Li, Y.; Peng, H.; Van Tendeloo, G.; Zhao, K.; Wu, J. |
| Title |
High-voltage cycling induced thermal vulnerability in LiCoO₂ cathode : cation loss and oxygen release driven by oxygen vacancy migration |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Acs Nano |
Abbreviated Journal |
Acs Nano |
| Volume |
14 |
Issue |
5 |
Pages |
6181-6190 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
The release of the lattice oxygen due to the thermal degradation of layered lithium transition metal oxides is one of the major safety concerns in Li-ion batteries. The oxygen release is generally attributed to the phase transitions from the layered structure to spinel and rocksalt structures that contain less lattice oxygen. Here, a different degradation pathway in LiCoO2 is found, through oxygen vacancy facilitated cation migration and reduction. This process leaves undercoordinated oxygen that gives rise to oxygen release while the structure integrity of the defect-free region is mostly preserved. This oxygen release mechanism can be called surface degradation due to the kinetic control of the cation migration but has a slow surface to bulk propagation with continuous loss of the surface cation ions. It is also strongly correlated with the high-voltage cycling defects that end up with a significant local oxygen release at low temperatures. This work unveils the thermal vulnerability of high-voltage Li-ion batteries and the critical role of the surface fraction as a general mitigating approach. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000537682300101 |
Publication Date |
2020-04-17 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1936-0851 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
17.1 |
Times cited |
8 |
Open Access |
Not_Open_Access |
| Notes |
; C.S., X.L., and F.X. contributed equally to this work. This work was supported by the National Natural Science Foundation of China (21905169). The S/TEM work was performed at the Nanostructure Research Center (NRC), which is supported by the Fundamental Research Funds for the Central Universities (WUT: 2019III012GX), the State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, and the State Key Laboratory of Silicate Materials for Architectures (all of the laboratories are at Wuhan University of Technology). ; |
Approved |
Most recent IF: 17.1; 2020 IF: 13.942 |
| Call Number |
UA @ admin @ c:irua:170246 |
Serial |
6537 |
| Permanent link to this record |
| |
|
| |
| Author |
Khanam, A.; Vohra, A.; Slotte, J.; Makkonen, I.; Loo, R.; Pourtois, G.; Vandervorst, W. |
| Title |
A demonstration of donor passivation through direct formation of V-As-i complexes in As-doped Ge1-XSnx |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Journal Of Applied Physics |
Abbreviated Journal |
J Appl Phys |
| Volume |
127 |
Issue |
19 |
Pages |
195703 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
Positron annihilation spectroscopy in the Doppler and coincidence Doppler mode was applied on Ge1 xSnx epitaxial layers, grown by chemical vapor deposition with different total As concentrations (1019-1021 cm3), high active As concentrations (1019 cm3), and similar Sn concentrations (5.9%-6.4%). Positron traps are identified as mono-vacancy complexes. Vacancy-As complexes, V-Asi, formed during the growth were studied to deepen the understanding of the electrical passivation of the Ge1 xSnx:As epilayers. Larger monovacancy complexes, V-Asi (i 2), are formed as the As doping increases. The total As concentration shows a significant impact on the saturation of the number of As atoms (i 1/4 4) around the vacancies in the sample epilayers. The presence of V-Asi complexes decreases the dopant activation in the Ge1 xSnx:As epilayers. Furthermore, the presence of Sn failed to hinder the formation of larger V-Asi complexes and thus failed to reduce the donor-deactivation. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000536196000003 |
Publication Date |
2020-05-15 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0021-8979; 1089-7550 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.2 |
Times cited |
|
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 3.2; 2020 IF: 2.068 |
| Call Number |
UA @ admin @ c:irua:170252 |
Serial |
6447 |
| Permanent link to this record |
| |
|
| |
| Author |
Dong, H.M.; Tao, Z.H.; Li, L.L.; Huang, F.; Xu, W.; Peeters, F.M. |
| Title |
Substrate dependent terahertz response of monolayer WS₂ |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Applied Physics Letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
116 |
Issue |
20 |
Pages |
1-4 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We investigate experimentally the terahertz (THz) optoelectronic properties of monolayer (ML) tungsten disulfide (WS2) placed on different substrates using THz time-domain spectroscopy (TDS). We find that the THz optical response of n-type ML WS2 depends sensitively on the choice of the substrate. This dependence is found to be a consequence of substrate induced charge transfer, extra scattering centers, and electronic localization. Through fitting the experimental results with the Drude-Smith formula, we can determine the key sample parameters (e.g., the electronic relaxation time, electron density, and electronic localization factor) of ML WS2 on different substrates. The temperature dependence of these parameters is examined. Our results show that the THz TDS technique is an efficient non-contact method that can be utilized to characterize and investigate the optoelectronic properties of nano-devices based on ML WS2. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000536282300001 |
Publication Date |
2020-05-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0003-6951; 1077-3118 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4 |
Times cited |
10 |
Open Access |
|
| Notes |
; This work was supported by the Fundamental Research Funds for the Central Universities (Grant No. 2018GF09) and by the National Natural Science foundation of China (Nos. U1930116 and 11574319). ; |
Approved |
Most recent IF: 4; 2020 IF: 3.411 |
| Call Number |
UA @ admin @ c:irua:170255 |
Serial |
6620 |
| Permanent link to this record |
| |
|
| |
| Author |
Lu, Y.; Liu, X.-L.; He, L.; Zhang, Y.-X.; Hu, Z.-Y.; Tian, G.; Cheng, X.; Wu, S.-M.; Li, Y.-Z.; Yang, X.-H.; Wang, L.-Y.; Liu, J.-W.; Janiak, C.; Chang, G.-G.; Li, W.-H.; Van Tendeloo, G.; Yang, X.-Y.; Su, B.-L. |
| Title |
Spatial heterojunction in nanostructured TiO₂ and its cascade effect for efficient photocatalysis |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Nano Letters |
Abbreviated Journal |
Nano Lett |
| Volume |
20 |
Issue |
5 |
Pages |
3122-3129 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
A highly efficient photoenergy conversion is strongly dependent on the cumulative cascade efficiency of the photogenerated carriers. Spatial heterojunctions are critical to directed charge transfer and, thus, attractive but still a challenge. Here, a spatially ternary titanium-defected TiO2@carbon quantum dots@reduced graphene oxide (denoted as V-Ti@CQDs@rGO) in one system is shown to demonstrate a cascade effect of charges and significant performances regarding the photocurrent, the apparent quantum yield, and photocatalysis such as H-2 production from water splitting and CO2 reduction. A key aspect in the construction is the technologically irrational junction of Ti-vacancies and nanocarbons for the spatially inside-out heterojunction. The new “spatial heterojunctions” concept, characteristics, mechanism, and extension are proposed at an atomic- nanoscale to clarify the generation of rational heterojunctions as well as the cascade electron transfer. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000535255300024 |
Publication Date |
2020-04-28 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1530-6984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
10.8 |
Times cited |
5 |
Open Access |
Not_Open_Access |
| Notes |
; This work was supported by the joint National Natural Science Foundation of China-Deutsche Forschungsgemeinschaft (NSFC-DFG) project (NSFC grant 51861135313, DFG JA466/39-1), Fundamental Research Funds for the Central Universities (19lgpy113, 19lgzd16), Program for Changjiang Scholars and Innovative Research Team in University (IRT_15R52) and Jilin Province Science and Technology Development Plan (20180101208JC). ; |
Approved |
Most recent IF: 10.8; 2020 IF: 12.712 |
| Call Number |
UA @ admin @ c:irua:170263 |
Serial |
6608 |
| Permanent link to this record |
| |
|
| |
| Author |
Bekaert, J.; Khestanova, E.; Hopkinson, D.G.; Birkbeck, J.; Clark, N.; Zhu, M.; Bandurin, D.A.; Gorbachev, R.; Fairclough, S.; Zou, Y.; Hamer, M.; Terry, D.J.; Peters, J.J.P.; Sanchez, A.M.; Partoens, B.; Haigh, S.J.; Milošević, M.V.; Grigorieva, I., V |
| Title |
Enhanced superconductivity in few-layer TaS₂ due to healing by oxygenation |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Nano Letters |
Abbreviated Journal |
Nano Lett |
| Volume |
20 |
Issue |
5 |
Pages |
3808-3818 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
When approaching the atomically thin limit, defects and disorder play an increasingly important role in the properties of two-dimensional (2D) materials. While defects are generally thought to negatively affect superconductivity in 2D materials, here we demonstrate the contrary in the case of oxygenation of ultrathin tantalum disulfide (TaS2). Our first-principles calculations show that incorporation of oxygen into the TaS2 crystal lattice is energetically favorable and effectively heals sulfur vacancies typically present in these crystals, thus restoring the electronic band structure and the carrier density to the intrinsic characteristics of TaS2. Strikingly, this leads to a strong enhancement of the electron-phonon coupling, by up to 80% in the highly oxygenated limit. Using transport measurements on fresh and aged (oxygenated) few-layer TaS2, we found a marked increase of the superconducting critical temperature (T-c) upon aging, in agreement with our theory, while concurrent electron microscopy and electron-energy loss spectroscopy confirmed the presence of sulfur vacancies in freshly prepared TaS2 and incorporation of oxygen into the crystal lattice with time. Our work thus reveals the mechanism by which certain atomic-scale defects can be beneficial to superconductivity and opens a new route to engineer T-c in ultrathin materials. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000535255300114 |
Publication Date |
2020-04-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1530-6984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
10.8 |
Times cited |
16 |
Open Access |
|
| Notes |
; This work was supported by Research Foundation-Flanders (FWO). J.Be. acknowledges support of a postdoctoral fellowship of the 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. S.J.H., D.H., and S.F. would like to thank the Engineering and Physical Sciences Research Council (EPSRC) U.K (grants EP/R031711/1, EP/P009050/1 and the Graphene NOWNANO CDT) and the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement ERC-2016-STG-EvoluTEM-715502, the Hetero2D Synergy grant and EC-FET Graphene Flagship) for funding. We thank Diamond Light Source for access and support in use of the electron Physical Science Imaging Centre (Instrument E02 and proposal numbers EM19315 and MG21597) that contributed to the results presented here. ; |
Approved |
Most recent IF: 10.8; 2020 IF: 12.712 |
| Call Number |
UA @ admin @ c:irua:170264 |
Serial |
6507 |
| Permanent link to this record |
| |
|
| |
| Author |
Han, Y.; Zeng, Y.; Hendrickx, M.; Hadermann, J.; Stephens, P.W.; Zhu, C.; Grams, C.P.; Hemberger, J.; Frank, C.; Li, S.; Wu, M.X.; Retuerto, M.; Croft, M.; Walker, D.; Yao, D.-X.; Greenblatt, M.; Li, M.-R. |
| Title |
Universal a-cation splitting in LiNbO₃-type structure driven by intrapositional multivalent coupling |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Journal Of The American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
| Volume |
142 |
Issue |
15 |
Pages |
7168-7178 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Understanding the electric dipole switching in multiferroic materials requires deep insight of the atomic-scale local structure evolution to reveal the ferroelectric mechanism, which remains unclear and lacks a solid experimental indicator in high-pressure prepared LiNbO3-type polar magnets. Here, we report the discovery of Zn-ion splitting in LiNbO3-type Zn2FeNbO6 established by multiple diffraction techniques. The coexistence of a high-temperature paraelectric-like phase in the polar Zn2FeNbO6 lattice motivated us to revisit other high-pressure prepared LiNbO3-type A(2)BB'O-6 compounds. The A-site atomic splitting (similar to 1.0-1.2 angstrom between the split-atom pair) in B/B'-mixed Zn2FeTaO6 and O/N-mixed ZnTaO2N is verified by both powder X-ray diffraction structural refinements and high angle annular dark field scanning transmission electron microscopy images, but is absent in single-B-site ZnSnO3. Theoretical calculations are in good agreement with experimental results and suggest that this kind of A-site splitting also exists in the B-site mixed Mn-analogues, Mn2FeMO6 (M = Nb, Ta) and anion-mixed MnTaO2N, where the smaller A-site splitting (similar to 0.2 angstrom atomic displacement) is attributed to magnetic interactions and bonding between A and B cations. These findings reveal universal A-site splitting in LiNbO3-type structures with mixed multivalent B/B', or anionic sites, and the splitting-atomic displacement can be strongly suppressed by magnetic interactions and/or hybridization of valence bands between d electrons of the A- and B-site cations. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000526300600046 |
Publication Date |
2020-03-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0002-7863 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
15 |
Times cited |
1 |
Open Access |
Not_Open_Access |
| Notes |
; This work was supported by the National Science Foundation of China (NSFC-21875287), the Program for Guangdong Introducing Innovative and Entrepreneurial Teams (2017ZT07C069), and an NSF-DMR-1507252 grant (U.S.). Use of the NSLS, Brookhaven National Laboratory, was supported by the DOE BES (DE-AC02-98CH10886). M.R. is thankful for the Spanish Juan de la Cierva grant FPDI-2013-17582. Y.Z. and D.-X.Y. are supported by NKRDPC-2018YFA0306001, NKRDPC-2017YFA0206203, NSFC-11974432, NSFG-2019A1515011337, the National Supercomputer Center in Guangzhou, and the Leading Talent Program of Guangdong Special Projects. Work on IOP, CAS, was supported by NSFC and MOST grants. A portion of this research at ORNL's Spallation Neutron Source was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. J.H. and M.H. thank the FWO for support for the electron microscopy studies through grant G035619N. We thank beamline BL14B1 (Shanghai Synchrotron Radiation Facility) for providing beam time and help during the experiments. ; |
Approved |
Most recent IF: 15; 2020 IF: 13.858 |
| Call Number |
UA @ admin @ c:irua:170294 |
Serial |
6646 |
| Permanent link to this record |
| |
|
| |
| Author |
Bacaksiz, C.; Yagmurcukardes, M.; Peeters, F.M.; Milošević, M.V. |
| Title |
Hematite at its thinnest limit |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
2d Materials |
Abbreviated Journal |
2D Mater |
| Volume |
7 |
Issue |
2 |
Pages |
025029 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Motivated by the recent synthesis of two-dimensional alpha-Fe2O3 (Balan et al 2018 Nat. Nanotechnol. 13 602), we analyze the structural, vibrational, electronic and magnetic properties of single- and few-layer alpha-Fe2O3 compared to bulk, by ab initio and Monte-Carlo simulations. We reveal how monolayer alpha-Fe2O3 (hematene) can be distinguished from the few-layer structures, and how they all differ from bulk through observable Raman spectra. The optical spectra exhibit gradual shift of the prominent peak to higher energy, as well as additional features at lower energy when alpha-Fe2O3 is thinned down to a monolayer. Both optical and electronic properties have strong spin asymmetry, meaning that lower-energy optical and electronic activities are allowed for the single-spin state. Finally, our considerations of magnetic properties reveal that 2D hematite has anti-ferromagnetic ground state for all thicknesses, but the critical temperature for Morin transition increases with decreasing sample thickness. On all accounts, the link to available experimental data is made, and further measurements are prompted. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000537341000002 |
Publication Date |
2020-01-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2053-1583 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
5.5 |
Times cited |
11 |
Open Access |
|
| Notes |
; This work was supported by Research Foundation-Flanders (FWO-Vlaanderen). Computational resources were provided by Flemish Supercomputer Center(VSC), and TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). Part of this work was also supported by FLAG-ERA project TRANS-2D-TMD and TOPBOF-UAntwerp. MY was supported by a postdoctoral fellowship from the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 5.5; 2020 IF: 6.937 |
| Call Number |
UA @ admin @ c:irua:170301 |
Serial |
6533 |
| Permanent link to this record |
| |
|
| |
| Author |
Reijniers, J.; Partoens, B.; Steckel, J.; Peremans, H. |
| Title |
HRTF measurement by means of unsupervised head movements with respect to a single fixed speaker |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Ieee Access |
Abbreviated Journal |
Ieee Access |
| Volume |
8 |
Issue |
|
Pages |
92287-92300 |
| Keywords |
A1 Journal article; Mass communications; Engineering Management (ENM); Condensed Matter Theory (CMT); Co-Design of Cyber-Physical Systems (Cosys-Lab) |
| Abstract |
In a standard state-of-the-art measurement the head-related transfer function (HRTF) is obtained in an anechoic room with an elaborate setup involving multiple calibrated loudspeakers. In search for a simplified method that would open up the possibility for an HRTF measurement in a home environment, it has been suggested that this setup could be replaced with one with a single, fixed loudspeaker. In such a setup, the subject samples different directions by moving the head with respect to this loudspeaker, while the head movements are tracked in some way. In this paper, the feasibility of such an approach is studied. To this end, the HRTF is measured in an unmodified (non-anechoic) room by means of a single external speaker and a high resolution head tracking system. The differences between the dynamically obtained HRTF and the standard static HRTF are investigated, and are shown to be mostly due to variable torso reflections. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000539041600001 |
Publication Date |
2020-05-15 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2169-3536 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.9 |
Times cited |
4 |
Open Access |
|
| Notes |
; This work was supported in part by the Research Foundation Flanders (FWO) under Grant G023619N, and in part by the Agency for Innovation and Entrepreneurship (VLAIO). ; |
Approved |
Most recent IF: 3.9; 2020 IF: 3.244 |
| Call Number |
UA @ admin @ c:irua:170318 |
Serial |
6539 |
| Permanent link to this record |
| |
|
| |
| Author |
Marteleur, M.; Idrissi, H.; Amin-Ahmadi, B.; Prima, F.; Schryvers, D.; Jacques, P.J. |
| Title |
On the nucleation mechanism of {112} < 111 > mechanical twins in as-quenched beta metastable Ti-12 wt.% Mo alloy |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Materialia |
Abbreviated Journal |
|
| Volume |
7 |
Issue |
|
Pages |
Unsp 100418 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Recently developed beta-metastable Ti grades take advantage of the simultaneous activation of TRIP and TWIP effects for enhancing their work hardening rate. However, the role of each plasticity mechanism on the macroscopic mechanical response is still unclear. In this work, the nucleation mechanism of the first activated plasticity mechanism, namely {112} < 111 > twinning, was investigated. Firstly, post-mortem TEM analysis showed that twins nucleate on pre-existing microstructural defects such as thermal jogs with the zonal dislocation mechanism. The precipitation of the omega phase on twin boundaries has been observed, as well as the emission of numerous dislocations from super-jogs present in these twin boundaries. It is also shown that {112} < 111 > twins act as effective dislocation sources for the subsequent plasticity mechanisms such as beta -> alpha '' martensitic transformation and {332} < 111 > twinning. Secondly, in situ TEM tensile testing of the investigated Ti grade highlighted the primary role of the initial defect configuration present in the microstructure. It is shown that twins cannot nucleate without the presence of specific defects allowing the triggering of the dislocation decomposition needed for the twinning mechanism highlighted in investigated bulk samples. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000537131000052 |
Publication Date |
2019-07-31 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2589-1529 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
no |
| Call Number |
UA @ admin @ c:irua:170326 |
Serial |
6875 |
| Permanent link to this record |
| |
|
| |
| Author |
De Paepe, J.; De Paepe, K.; Gòdia, F.; Rabaey, K.; Vlaeminck, S.E.; Clauwaert, P. |
| Title |
Bio-electrochemical COD removal for energy-efficient, maximum and robust nitrogen recovery from urine through membrane aerated nitrification |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Water Research |
Abbreviated Journal |
Water Res |
| Volume |
185 |
Issue |
|
Pages |
116223 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
Resource recovery from source-separated urine can shorten nutrient cycles on Earth and is essential in regenerative life support systems for deep-space exploration. In this study, a robust two-stage, energy-efficient, gravity-independent urine treatment system was developed to transform fresh real human urine into a stable nutrient solution. In the first stage, up to 85% of the COD was removed in a microbial electrolysis cell (MEC), converting part of the energy in organic compounds (27-46%) into hydrogen gas and enabling full nitrogen recovery by preventing nitrogen losses through denitrification in the second stage. Besides COD removal, all urea was hydrolysed in the MEC, resulting in a stream rich in ammoniacal nitrogen and alkalinity, and low in COD. This stream was fed into a membrane-aerated biofilm reactor (MABR) in order to convert the volatile and toxic ammoniacal nitrogen to non-volatile nitrate by nitrification. Bio-electrochemical pre-treatment allowed to recover all nitrogen as nitrate in the MABR at a bulk-phase dissolved oxygen level below 0.1 mg O2 L-1. In contrast, feeding the MABR directly with raw urine (omitting the first stage), at the same nitrogen loading rate, resulted in nitrogen loss (18%) due to denitrification. The MEC and MABR were characterised by very distinct and diverse microbial communities. While (strictly) anaerobic genera, such as Geobacter (electroactive bacteria), Thiopseudomonas, a Lentimicrobiaceae member, Alcaligenes and Proteiniphilum prevailed in the MEC, the MABR was dominated by aerobic genera, including Nitrosomonas (a known ammonium oxidiser), Moheibacter and Gordonia. The two-stage approach yielded a stable nitrate-rich, COD-low nutrient solution, suitable for plant and microalgae cultivation. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000580639800035 |
Publication Date |
2020-07-23 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0043-1354 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
12.8 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 12.8; 2020 IF: 6.942 |
| Call Number |
UA @ admin @ c:irua:170524 |
Serial |
6461 |
| Permanent link to this record |
| |
|
| |
| Author |
Alloul, A.; Wille, M.; Lucenti, P.; Bossier, P.; Van Stappen, G.; Vlaeminck, S.E. |
| Title |
Purple bacteria as added-value protein ingredient in shrimp feed : Penaeus vannamei growth performance, and tolerance against Vibrio and ammonia stress |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Aquaculture |
Abbreviated Journal |
Aquaculture |
| Volume |
530 |
Issue |
|
Pages |
735788 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
Aquafeeds contain protein ingredients such as fishmeal and soybean meal, yet their production puts pressure on the environment. Finding novel protein sources such as dried microbial biomass produced on recovered or renewable resources, so-called single-cell protein or microbial protein, can contribute to a more sustainable aquaculture industry. New microbial protein sources are emerging with photoheterotrophic grown purple non‑sulfur bacteria (PNSB) showing high potential, yet research of PNSB as added-value protein ingredient is limited. This research studied their use as a protein source for the white leg shrimp (Penaeus vannamei) and investigated the shrimp's tolerance against Vibrio and ammonia stress. A 28-day shrimp feeding trial was performed with a commercial formulation without PNSB as experimental control (diet i), two pure PNSB species, namely Rhodopseudomonas palustris (diets ii-iii), Rhodobacter capsulatus (diets iv-v) at two protein inclusion levels of 5 and 11 g PNSBprotein 100 g−1 feedprotein and a PNSB enriched culture at a protein inclusion level of 11 g PNSBprotein 100 g−1 feedprotein (diet vi). For the shrimp fed with Rb. capsulatus, 5–25% higher individual weights (p < .05) and better feed conversion ratios were observed relative to the commercial diet (1.3–1.4 vs. control 1.7 g feed g−1 biomass; p < .05). The diet containing Rps. palustris at 5 g PNSBprotein 100 g−1 feedprotein inclusion also showed higher individual weights (26%, p < .05) and a better feed conversion ratio compared to the commercial feed (1.3 vs. control 1.7 g feed g−1 biomass; p < .05). The challenge test subsequent to the feeding trial showed a higher tolerance against ammonia (3 mg N L−1) for shrimp fed with Rps. palustris (survival 63–75% vs. 8% commercial diet; p < .05). For a post-feeding challenge test with Vibrio parahaemolyticus TW01, mortality rates were equal among all treatments. Yet, in vitro tests in 96-Well plates and agar spot assays showed that the PNSB species (i) Rps. palustris, (ii) Rb. capsulatus, (iii) Rb. sphaeroides, (iv) Rhodospirillum rubrum and (v) Afifella marina suppressed the pathogens V. parahaemolyticus TW01 and V. campbellii LMG 21363. Overall, this study demonstrated the potential of PNSB as an added-value protein ingredient in shrimp nursery feed. This can contribute to a circular economy, as PNSB can be cultivated on recovered or renewable resources (e.g. wastewater). |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000582169700073 |
Publication Date |
2020-08-08 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0044-8486 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.57 |
Times cited |
|
Open Access |
OpenAccess |
| Notes |
|
Approved |
Most recent IF: 2.57 |
| Call Number |
UA @ admin @ c:irua:170549 |
Serial |
8429 |
| Permanent link to this record |
| |
|
| |
| Author |
Ben Dkhil, S.; Perkhun, P.; Luo, C.; Mueller, D.; Alkarsifi, R.; Barulina, E.; Quiroz, Y.A.A.; Margeat, O.; Dubas, S.T.; Koganezawa, T.; Kuzuhara, D.; Yoshimoto, N.; Caddeo, C.; Mattoni, A.; Zimmermann, B.; Wuerfel, U.; Pfannmöller, M.; Bals, S.; Ackermann, J.; Videlot-Ackermann, C. |
| Title |
Direct correlation of nanoscale morphology and device performance to study photocurrent generation in donor-enriched phases of polymer solar cells |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Acs Applied Materials & Interfaces |
Abbreviated Journal |
Acs Appl Mater Inter |
| Volume |
12 |
Issue |
25 |
Pages |
28404-28415 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
The nanoscale morphology of polymer blends is a key parameter to reach high efficiency in bulk heterojunction solar cells. Thereby, research typically focusing on optimal blend morphologies while studying nonoptimized blends may give insight into blend designs that can prove more robust against morphology defects. Here, we focus on the direct correlation of morphology and device performance of thieno[3,4-b]-thiophene-alt-benzodithiophene (PTB7):[6,6]phenyl C-71 butyric acid methyl ester (PC71BM) bulk heterojunction (BHJ) blends processed without additives in different donor/acceptor weight ratios. We show that while blends of a 1:1.5 ratio are composed of large donor-enriched and fullerene domains beyond the exciton diffusion length, reducing the ratio below 1:0.5 leads to blends composed purely of polymer-enriched domains. Importantly, the photocurrent density in such blends can reach values between 45 and 60% of those reached for fully optimized blends using additives. We provide here direct visual evidence that fullerenes in the donor-enriched domains are not distributed homogeneously but fluctuate locally. To this end, we performed compositional nanoscale morphology analysis of the blend using spectroscopic imaging of low-energy-loss electrons using a transmission electron microscope. Charge transport measurement in combination with molecular dynamics simulations shows that the fullerene substructures inside the polymer phase generate efficient electron transport in the polymer-enriched phase. Furthermore, we show that the formation of densely packed regions of fullerene inside the polymer phase is driven by the PTB7:PC71BM enthalpy of mixing. The occurrence of such a nanoscale network of fullerene clusters leads to a reduction of electron trap states and thus efficient extraction of photocurrent inside the polymer domain. Suitable tuning of the polymer-acceptor interaction can thus introduce acceptor subnetworks in polymer-enriched phases, improving the tolerance for high-efficiency BHJ toward morphological defects such as donor-enriched domains exceeding the exciton diffusion length. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000543780900058 |
Publication Date |
2020-06-01 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1944-8244 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
9.5 |
Times cited |
7 |
Open Access |
OpenAccess |
| Notes |
; J.A., O.M., and C.V.-A. acknowledge financial support by the French Fond Unique Interministeriel (FUI) under the project “SFUMATO” (Grant Number: F1110019V/ 201308815) as well as by the European Commission under the Project “SUNFLOWER” (FP7-ICT-2011-7, Grant Number: 287594). J.A., C.V.-A., and E.B. acknowledge the Association Nationale de la Recherche et de la Technologie (ANRT) and the Ministere de l'Enseignement Superieur, de la Recherche et de l'Innovation, awarded through the company Dracula Technologies (Valence, France), for framework of a CIFRE Ph.D. grant 2017/0529. J.A. and P.P. received funding from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant agreement no. 713750. They further acknowledge support of the Regional Council of Provence-Alpes-Cote d'Azur, A*MIDEX (no. ANR-11-IDEX-0001-02), and the Investissements d'Avenir project funded by the French Government, managed by the French National Research Agency (ANR). J.A. and Y.A.A.Q. acknowledge the French Research Agency for funding through the project NFA-15 (ANR-17-CE05-0020-01). N.Y. acknowledges that the synchrotron radiation experiments were performed at BL19B2 in SPring-8 with the approval of Japan Synchrotron Radiation Research Institute (JASRI) (proposal nos. 2017B1629 and 2018B1791). S.B. acknowledges financial support from the European Research Council (ERC Consolidator Grant 815128-REALNANO) and from FWO (G.0381.16N). M.P. gratefully acknowledges funding by the Ministerium fur Wissenschaft, Forschung und Kunst Baden-Wurttemberg through the HEiKA materials research centre FunTECH-3D (MWK, 33-753-30-20/3/3) and the Large-Scale-Data-Facility (LSDF) sds@hd through grant INST 35/1314-1 FUGG. A.M. acknowledges Italian MIUR for funding through the project PON04a2 00490 M2M Netergit, PRACE, for awarding access to Marconi KNL at CINECA, Italy, through projects DECONVOLVES (2018184466) and PROVING-IL (2019204911). C.C. acknowledges the CINECA award under the ISCRA initiative for the availability of high-performance computing resources and support (project MITOMASC). ; sygma |
Approved |
Most recent IF: 9.5; 2020 IF: 7.504 |
| Call Number |
UA @ admin @ c:irua:170703 |
Serial |
6484 |
| Permanent link to this record |
| |
|
| |
| Author |
Griffin, E.; Mogg, L.; Hao, G.-P.; Kalon, G.; Bacaksiz, C.; Lopez-Polin, G.; Zhou, T.Y.; Guarochico, V.; Cai, J.; Neumann, C.; Winter, A.; Mohn, M.; Lee, J.H.; Lin, J.; Kaiser, U.; Grigorieva, I., V; Suenaga, K.; Ozyilmaz, B.; Cheng, H.-M.; Ren, W.; Turchanin, A.; Peeters, F.M.; Geim, A.K.; Lozada-Hidalgo, M. |
| Title |
Proton and Li-Ion permeation through graphene with eight-atom-ring defects |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Acs Nano |
Abbreviated Journal |
Acs Nano |
| Volume |
14 |
Issue |
6 |
Pages |
7280-7286 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
Defect-free graphene is impermeable to gases and liquids but highly permeable to thermal protons. Atomic-scale defects such as vacancies, grain boundaries, and Stone-Wales defects are predicted to enhance graphene's proton permeability and may even allow small ions through, whereas larger species such as gas molecules should remain blocked. These expectations have so far remained untested in experiment. Here, we show that atomically thin carbon films with a high density of atomic-scale defects continue blocking all molecular transport, but their proton permeability becomes similar to 1000 times higher than that of defect-free graphene. Lithium ions can also permeate through such disordered graphene. The enhanced proton and ion permeability is attributed to a high density of eight-carbon-atom rings. The latter pose approximately twice lower energy barriers for incoming protons compared to that of the six-atom rings of graphene and a relatively low barrier of similar to 0.6 eV for Li ions. Our findings suggest that disordered graphene could be of interest as membranes and protective barriers in various Li-ion and hydrogen technologies. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000543744100086 |
Publication Date |
2020-05-19 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1936-0851 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
17.1 |
Times cited |
34 |
Open Access |
|
| Notes |
; The work was supported by the Lloyd's Register Foundation, EPSRC-EP/N010345/1, the European Research Council, the Graphene Flagship, the Deutsche Forschungsgemeinschaft project TRR 234 “CataLight” (Project B7, Grant No. 364549901), and the research infrastructure Grant No. INST 275/25 7-1 FUGG. E.G. and L.M. acknowledge the EPSRC NowNANO programme for funding. ; |
Approved |
Most recent IF: 17.1; 2020 IF: 13.942 |
| Call Number |
UA @ admin @ c:irua:170708 |
Serial |
6586 |
| Permanent link to this record |
| |
|
| |
| Author |
Reguera, J.; Flora, T.; Winckelmans, N.; Rodriguez-Cabello, J.C.; Bals, S. |
| Title |
Self-assembly of Janus Au:Fe₃O₄ branched nanoparticles. From organized clusters to stimuli-responsive nanogel suprastructures |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Nanoscale Advances |
Abbreviated Journal |
|
| Volume |
2 |
Issue |
6 |
Pages |
2525-2530 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Janus nanoparticles offer enormous possibilities through a binary selective functionalization and dual properties. Their self-assembly has attracted strong interest due to their potential as building blocks to obtain molecular colloids, supracrystals and well-organized nanostructures that can lead to new functionalities. However, this self-assembly has been focused on relatively simple symmetrical morphologies, while for complex nanostructures this process has been unexplored. Here, we study the assembly of plasmonic-magnetic Janus nanoparticles with a branched (nanostar) – sphere morphology. The branched morphology enhances their plasmonic properties in the near-infrared region and therefore their applicability, but at the same time constrains their self-assembly capabilities to obtain more organized or functional suprastructures. We describe the self-assembly of these nanoparticles after amphiphilic functionalization. The role of the nanoparticle branching, as well as the size of the polymer-coating, is explored. We show how the use of large molecular weight stabilizing polymers can overcome the anisotropy of the nanoparticles producing a change in the morphology from small clusters to larger quasi-cylindrical nanostructures. Finally, the Janus nanoparticles are functionalized with a thermo-responsive elastin-like recombinamer. These nanoparticles undergo reversible self-assembly in the presence of free polymer giving rise to nanoparticle-stabilized nanogel-like structures with controlled size, providing the possibility to expand their applicability to multi-stimuli controlled self-assembly. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000543283200032 |
Publication Date |
2020-04-22 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2516-0230 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.7 |
Times cited |
10 |
Open Access |
OpenAccess |
| Notes |
; J. R. acknowledges the.nancial support of Basque Country Elkartek-KK-2019/ 00101. T. F. and J. C. R-C acknowledge the funding from the European Commission (NMP-2014-646075), the Spanish Government (PCIN-2015-010 (FunBioPlas), MAT2016-78903-R), Junta de Castilla y Leon (VA317P18) and Centro en Red de Medicina Regenerativa y Terapia Celular de Castilla y Leon. ; |
Approved |
Most recent IF: 4.7; 2020 IF: NA |
| Call Number |
UA @ admin @ c:irua:170773 |
Serial |
6600 |
| Permanent link to this record |
| |
|
| |
| Author |
Yu, W.-B.; Hu, Z.-Y.; Jin, J.; Yi, M.; Yan, M.; Li, Y.; Wang, H.-E.; Gao, H.-X.; Mai, L.-Q.; Hasan, T.; Xu, B.-X.; Peng, D.-L.; Van Tendeloo, G.; Su, B.-L. |
| Title |
Unprecedented and highly stable lithium storage capacity of (001) faceted nanosheet-constructed hierarchically porous TiO₂/rGO hybrid architecture for high-performance Li-ion batteries |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
National Science Review |
Abbreviated Journal |
Natl Sci Rev |
| Volume |
7 |
Issue |
6 |
Pages |
1046-1058 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Active crystal facets can generate special properties for various applications. Herein, we report a (001) faceted nanosheet-constructed hierarchically porous TiO2/rGO hybrid architecture with unprecedented and highly stable lithium storage performance. Density functional theory calculations show that the (001) faceted TiO2 nanosheets enable enhanced reaction kinetics by reinforcing their contact with the electrolyte and shortening the path length of Li+ diffusion and insertion-extraction. The reduced graphene oxide (rGO) nanosheets in this TiO2/rGO hybrid largely improve charge transport, while the porous hierarchy at different length scales favors continuous electrolyte permeation and accommodates volume change. This hierarchically porous TiO2/rGO hybrid anode material demonstrates an excellent reversible capacity of 250 mAh g(-1) at 1 C (1 C = 335 mA g(-1)) at a voltage window of 1.0-3.0 V. Even after 1000 cycles at 5 C and 500 cycles at 10 C, the anode retains exceptional and stable capacities of 176 and 160 mAh g(-1), respectively. Moreover, the formed Li2Ti2O4 nanodots facilitate reversed Li+ insertion-extraction during the cycling process. The above results indicate the best performance of TiO2-based materials as anodes for lithium-ion batteries reported in the literature. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000544175300013 |
Publication Date |
2020-02-16 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2095-5138 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
20.6 |
Times cited |
3 |
Open Access |
OpenAccess |
| Notes |
; This work was supported by the National Key R&D Program of China (2016YFA0202602 and 2016YFA0202603), the National Natural Science Foundation of China (U1663225) and Program for Changjiang Scholars and Innovative Research Team in University (IRT_15R52). ; |
Approved |
Most recent IF: 20.6; 2020 IF: 8.843 |
| Call Number |
UA @ admin @ c:irua:170776 |
Serial |
6648 |
| Permanent link to this record |
| |
|
| |
| Author |
Bourgeois, L.; Zhang, Y.; Zhang, Z.; Chen, Y.; Medhekar, N., V |
| Title |
Transforming solid-state precipitates via excess vacancies |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Nature Communications |
Abbreviated Journal |
Nat Commun |
| Volume |
11 |
Issue |
1 |
Pages |
1248 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Many phase transformations associated with solid-state precipitation look structurally simple, yet, inexplicably, take place with great difficulty. A classic case of difficult phase transformations is the nucleation of strengthening precipitates in high-strength lightweight aluminium alloys. Here, using a combination of atomic-scale imaging, simulations and classical nucleation theory calculations, we investigate the nucleation of the strengthening phase theta' onto a template structure in the aluminium-copper alloy system. We show that this transformation can be promoted in samples exhibiting at least one nanoscale dimension, with extremely high nucleation rates for the strengthening phase as well as for an unexpected phase. This template-directed solid-state nucleation pathway is enabled by the large influx of surface vacancies that results from heating a nanoscale solid. Template-directed nucleation is replicated in a bulk alloy as well as under electron irradiation, implying that this difficult transformation can be facilitated under the general condition of sustained excess vacancy concentrations. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000549162600025 |
Publication Date |
2020-03-06 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
16.6 |
Times cited |
5 |
Open Access |
OpenAccess |
| Notes |
; The authors are indebted to Matthew Weyland for his expert advice on aberrationcorrected scanning transmission electron microscopy. L.B. would like to acknowledge initial discussions with B.C. Muddle and J.F. Nie many years ago regarding the possible thermodynamic role of vacancies in solid-state precipitation. The authors acknowledge funding from the Australian Research Council (LE0454166, LE110100223), the Victorian State Government and Monash University for instrumentation, and use of the facilities within the Monash Centre for Electron Microscopy. The authors thank Flame Burgmann, Dougal McCulloch and Edwin Mayes for access to and assistance at the Microscopy and Microanalysis Facility at RMIT University. L.B. and N.M. acknowledge the financial support of the Australian Research Council (DP150100558). Authors also gratefully acknowledge the computational support from MonARCH, MASSIVE and the National Computing Infrastructure and Pawsey Supercomputing Centre. ZZ and YZ are thankful to Monash University for a Monash Graduate Scholarship, a Monash International Postgraduate Research Scholarship. Z.Z. is grateful for a Monash Centre for Electron Microscopy Postgraduate Scholarship. The authors are grateful to Anita Hill for advice. ; |
Approved |
Most recent IF: 16.6; 2020 IF: 12.124 |
| Call Number |
UA @ admin @ c:irua:170797 |
Serial |
6635 |
| Permanent link to this record |
| |
|
| |
| Author |
De Jong, M. |
| Title |
A highly accurate portable electrochemical sensor for cocaine : from methodology to testing in the field |
Type |
Doctoral thesis |
| Year |
2020 |
Publication |
|
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
263 p. |
| Keywords |
Doctoral thesis; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
|
Publication Date |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Additional Links |
UA library record |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ admin @ c:irua:170912 |
Serial |
6538 |
| Permanent link to this record |
| |
|
| |
| Author |
Cagno, S.; van der Snickt, G.; Legrand, S.; Caen, J.; Patin, M.; Meulebroeck, W.; Dirkx, Y.; Hillen, M.; Steenackers, G.; Rousaki, A.; Vandenabeele, P.; Janssens, K. |
| Title |
Comparison of four mobile, non‐invasive diagnostic techniques for differentiating glass types in historical leaded windows : MA‐XRF , UV–Vis–NIR, Raman spectroscopy and IRT |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
X-Ray Spectrometry |
Abbreviated Journal |
X-Ray Spectrom |
| Volume |
|
Issue |
|
Pages |
xrs.3185-17 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES) |
| Abstract |
This paper critically compares the performance of four non-invasive techniques that match the accuracy, flexibility, time-efficiency, and transportability required for in situ characterization of leaded glass windows: macroscopic X-ray fluorescence imaging (MA-XRF), UV-Vis-NIR, Raman spectroscopy, and infrared thermography (IRT). In order to compare the techniques on equal grounds, all techniques were tested independently of each other by separate research groups on the same historical leaded window tentatively dated to the 17th century, without prior knowledge. The aim was to assess the ability of these techniques to document the conservation history of the window by classifying and grouping the colorless glass panes, based on differences in composition. IRT, MA-XRF and UV-Vis-NIR spectroscopy positively distinguished at least two glass groups, with MA-XRF providing the most detailed chemical information. In particular, based on the ratio between the network modifier (K) and network stabilizer (Ca) and on the level of colorants and decolorizers (Fe, Mn, As), the number of plausible glass families could be strongly reduced. In addition, UV-Vis-NIR detected cobalt at ppm level and gave more specific information on the chromophore Fe2+/Fe(3+)ratio. Raman spectroscopy was hampered by fluorescence caused by the metal ions of the decolorizer in most of the panes, but nevertheless identified one group as HLLA. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000561869600001 |
Publication Date |
2020-08-24 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0049-8246 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.2 |
Times cited |
|
Open Access |
|
| Notes |
; Belgian Federal Science Policy Office, Grant/Award Number: BR/175/A3/FENESTRA; Fonds Wetenschappelijk Onderzoek, Grant/Award Number: 12X1919N; Baillet-Latour Fund ; |
Approved |
Most recent IF: 1.2; 2020 IF: 1.298 |
| Call Number |
UA @ admin @ c:irua:170972 |
Serial |
6473 |
| Permanent link to this record |
| |
|
| |
| Author |
Zhu, W.; Li, J.; Wang, B.; Chen, G. |
| Title |
Enhancement of pollutants removal from saline wastewater through simultaneous anammox and denitrification (SAD) process with glycine betaine addition |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Bioresource Technology |
Abbreviated Journal |
Bioresource Technol |
| Volume |
315 |
Issue |
|
Pages |
123784 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
Enhanced pollutants removal from saline wastewater was investigated in simultaneous anammox and denitrification (SAD) process with glycine betaine (GB) addition. Long-term operation indicated the optimal GB dose was around 0.4 mM, which enhanced both anammox and denitrifying activity by 30% and 45%, respectively. The total nitrogen and organic removal rates were 0.38 +/- 0.2 kgN/m(3)/d and 0.34 +/- 0.3 kgCOD/m(3)/d, respectively, which increased by 34.5% and 20.5%. Independent of GB dose, denitrifying activity was promoted, but anammox activity was drastically deteriorated after excessive GB addition. The optimal GB dose predicated by both Gaussian and Modified-Boltzmann models were 0.42-0.45 mM. Besides, the bacterial activity recovery after excessive GB addition could be analyzed by the Modified-Boltzmann model. With 1.5 mM GB, granular floatation occurred since numerous gas bubbles were inside the granules. In general, exogenous GB addition can mitigate salinity inhibition and promote pollutants removal from saline wastewater. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000560717900013 |
Publication Date |
2020-07-06 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0960-8524 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
11.4 |
Times cited |
1 |
Open Access |
|
| Notes |
; This study was financially supported by the National Natural Science Foundation of China (51878362), China Postdoctoral Science Foundation (2017M610410, 2018T110665) and State Key Joint Laboratory of Environment Simulation and Pollution Control (Research Center for Eco-environmental Sciences, Chinese Academy of Sciences) (18K02ESPCR). The authors also thank Dr. Yuan Hou and Dr. Chao Fang from University of Antwerp for numerous discussion. ; |
Approved |
Most recent IF: 11.4; 2020 IF: 5.651 |
| Call Number |
UA @ admin @ c:irua:171118 |
Serial |
6508 |
| Permanent link to this record |
| |
|
| |
| Author |
Mehta, A.N.; Gauquelin, N.; Nord, M.; Orekhov, A.; Bender, H.; Cerbu, D.; Verbeeck, J.; Vandervorst, W. |
| Title |
Unravelling stacking order in epitaxial bilayer MX₂ using 4D-STEM with unsupervised learning |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
| Volume |
31 |
Issue |
44 |
Pages |
445702 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Following an extensive investigation of various monolayer transition metal dichalcogenides (MX2), research interest has expanded to include multilayer systems. In bilayer MX2, the stacking order strongly impacts the local band structure as it dictates the local confinement and symmetry. Determination of stacking order in multilayer MX(2)domains usually relies on prior knowledge of in-plane orientations of constituent layers. This is only feasible in case of growth resulting in well-defined triangular domains and not useful in-case of closed layers with hexagonal or irregularly shaped islands. Stacking order can be discerned in the reciprocal space by measuring changes in diffraction peak intensities. Advances in detector technology allow fast acquisition of high-quality four-dimensional datasets which can later be processed to extract useful information such as thickness, orientation, twist and strain. Here, we use 4D scanning transmission electron microscopy combined with multislice diffraction simulations to unravel stacking order in epitaxially grown bilayer MoS2. Machine learning based data segmentation is employed to obtain useful statistics on grain orientation of monolayer and stacking in bilayer MoS2. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000561424400001 |
Publication Date |
2020-07-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0957-4484 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.5 |
Times cited |
13 |
Open Access |
OpenAccess |
| Notes |
; J.V. acknowledges funding from FLAG-ERA JTC2017 project 'Graph-Eye'. N.G. acknowledges funding from GOA project 'Solarpaint' of the University of Antwerp. This project has received funding from the European Union's Horizon 2020 research and innovation programme under Grant Agreement No. 823717-ESTEEM3. 4D STEM data was acquired on a hybrid pixel detector funded with a Hercules fund 'Direct electron detector for soft matter TEM' from the Flemish Government. M. N. acknowledges funding from a Marie Curie Fellowship agreement No 838001. We thank Dr Jiongjiong Mo and Dr Benjamin Groven for developing the CVD-MoS<INF>2</INF> growth on sapphire and providing the material used in this article. ; |
Approved |
Most recent IF: 3.5; 2020 IF: 3.44 |
| Call Number |
UA @ admin @ c:irua:171119 |
Serial |
6649 |
| Permanent link to this record |
| |
|
| |
| Author |
Yan, X.F.; Chen, Q.; Li, L.L.; Guo, H.Z.; Peng, J.Z.; Peeters, F.M. |
| Title |
High performance piezotronic spin transistors using molybdenum disulfide nanoribbon |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Nano Energy |
Abbreviated Journal |
Nano Energy |
| Volume |
75 |
Issue |
|
Pages |
104953 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
Two-dimensional (2D) materials are promising candidates for atomic-scale piezotronics and piezophototronics. Quantum edge states show fascinating fundamental physics such as nontrivial topological behavior and hold promising practical applications for low-power electronic devices. Here, using the tight-binding approach and quantum transport simulations, we investigate the piezotronic effect on the spin polarization of edge states in a zigzag-terminated monolayer MoS2 nanoribbon. We find that the strain-induced piezoelectric potential induces a phase transition of edge states from metal to semiconductor. However, in the presence of exchange field, edge states become semi-metallic with significant spin splitting and polarization that can be tuned by external strain. We show that quantum transport conductance exhibits a 100% spin polarization over a wide range of strain magnitudes. This effect is used in a propose prototype of piezotronic spin transistor. Our results provide a fundamental understanding of the piezotronic effect on edge states in zigzag monolayer MoS2 nanoribbons and are relevant for designing high-performance piezotronic spin devices. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000560729200011 |
Publication Date |
2020-05-24 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2211-2855 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
17.6 |
Times cited |
17 |
Open Access |
|
| Notes |
; This work was supported by Hunan Provincial Natural Science Foundation of China (Nos. 2015JJ2040, 2018JJ2078), Scientific Research Fund of Hunan Provincial Education Department (19A106), and the Funeral Service Foundation (FWO-VI). ; |
Approved |
Most recent IF: 17.6; 2020 IF: 12.343 |
| Call Number |
UA @ admin @ c:irua:171123 |
Serial |
6535 |
| Permanent link to this record |
| |
|
| |
| Author |
Nicolas-Boluda, A.; Yang, Z.; Dobryden, I.; Carn, F.; Winckelmans, N.; Pechoux, C.; Bonville, P.; Bals, S.; Claesson, P.M.; Gazeau, F.; Pileni, M.P. |
| Title |
Intracellular fate of hydrophobic nanocrystal self-assemblies in tumor cells |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Advanced Functional Materials |
Abbreviated Journal |
Adv Funct Mater |
| Volume |
30 |
Issue |
40 |
Pages |
2004274-15 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Control of interactions between nanomaterials and cells remains a biomedical challenge. A strategy is proposed to modulate the intralysosomal distribution of nanoparticles through the design of 3D suprastructures built by hydrophilic nanocrystals (NCs) coated with alkyl chains. The intracellular fate of two water-dispersible architectures of self-assembled hydrophobic magnetic NCs: hollow deformable shells (colloidosomes) or solid fcc particles (supraballs) is compared. These two self-assemblies display increased cellular uptake by tumor cells compared to dispersions of the water-soluble NC building blocks. Moreover, the self-assembly structures increase the NCs density in lysosomes and close to the lysosome membrane. Importantly, the structural organization of NCs in colloidosomes and supraballs are maintained in lysosomes up to 8 days after internalization, whereas initially dispersed hydrophilic NCs are randomly aggregated. Supraballs and colloidosomes are differently sensed by cells due to their different architectures and mechanical properties. Flexible and soft colloidosomes deform and spread along the biological membranes. In contrast, the more rigid supraballs remain spherical. By subjecting the internalized suprastructures to a magnetic field, they both align and form long chains. Overall, it is highlighted that the mechanical and topological properties of the self-assemblies direct their intracellular fate allowing the control intralysosomal density, ordering, and localization of NCs. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000559913300001 |
Publication Date |
2020-08-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1616-301x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
19 |
Times cited |
11 |
Open Access |
Not_Open_Access |
| Notes |
; F.G. and M.P.P. contributed equally to this work. Dr. J. Teixeira from Laboratoire Leon Brillouin CEA Saclay is thanked for fruitful discussions on SAXS measurement. Dr. J.M. Guinier is thanked for cryoTEM experiments. A.N.-B. received a Ph.D. fellowship from the Institute thematique multi-organismes (ITMO) Cancer and the doctoral school Frontieres du Vivant (FdV)-Programme Bettencourt and the Fondation ARC pour la recherche sur le cancer. ; |
Approved |
Most recent IF: 19; 2020 IF: 12.124 |
| Call Number |
UA @ admin @ c:irua:171145 |
Serial |
6551 |
| Permanent link to this record |
| |
|
| |
| Author |
Topalovic, D.B.; Arsoski, V.V.; Tadic, M.Z.; Peeters, F.M. |
| Title |
Asymmetric versus symmetric HgTe/CdxHg1-x Te double quantum wells: Bandgap tuning without electric field |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Journal Of Applied Physics |
Abbreviated Journal |
J Appl Phys |
| Volume |
128 |
Issue |
6 |
Pages |
064301-64308 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We investigate the electron states in double asymmetric HgTe / Cd x Hg 1 – x Te quantum wells grown along the [ 001 ] direction. The subbands are computed by means of the envelope function approximation applied to the eight-band Kane k . mml:mspace width=“.1em”mml:mspace p model. The asymmetry of the confining potential of the double quantum wells results in a gap opening, which is absent in the symmetric system where it can only be induced by an applied electric field. The bandgap and the subbands are affected by spin-orbit coupling, which is a consequence of the asymmetry of the confining potential. The electron-like and hole-like states are mainly confined in different quantum wells, and the enhanced hybridization between them opens a spin-dependent hybridization gap at a finite in-plane wavevector. We show that both the ratio of the widths of the two quantum wells and the mole fraction of the C d x H g 1 – x Te barrier control both the energy gap between the hole-like states and the hybridization gap. The energy subbands are shown to exhibit inverted ordering, and therefore, a nontrivial topological phase could emerge in the system. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000561339300001 |
Publication Date |
2020-08-10 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0021-8979; 1089-7550 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.2 |
Times cited |
3 |
Open Access |
|
| Notes |
; This research was funded by the Ministry of Education, Science and Technological Development of the Republic of Serbia and the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.2; 2020 IF: 2.068 |
| Call Number |
UA @ admin @ c:irua:171146 |
Serial |
6453 |
| Permanent link to this record |
| |
|
| |
| Author |
Paulus, A.; Hendrickx, M.; Bercx, M.; Karakulina, O.M.; Kirsanova, M.A.; Lamoen, D.; Hadermann, J.; Abakumov, A.M.; Van Bael, M.K.; Hardy, A. |
| Title |
An in-depth study of Sn substitution in Li-rich/Mn-rich NMC as a cathode material for Li-ion batteries |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Journal of the Chemical Society : Dalton transactions |
Abbreviated Journal |
|
| Volume |
49 |
Issue |
30 |
Pages |
10486-10497 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Layered Li-rich/Mn-rich NMC (LMR-NMC) is characterized by high initial specific capacities of more than 250 mA h g(-1), lower cost due to a lower Co content and higher thermal stability than LiCoO2. However, its commercialisation is currently still hampered by significant voltage fade, which is caused by irreversible transition metal ion migration to emptied Li positionsviatetrahedral interstices upon electrochemical cycling. This structural change is strongly correlated with anionic redox chemistry of the oxygen sublattice and has a detrimental effect on electrochemical performance. In a fully charged state, up to 4.8 Vvs.Li/Li+, Mn4+ is prone to migrate to the Li layer. The replacement of Mn4+ for an isovalent cation such as Sn4+ which does not tend to adopt tetrahedral coordination and shows a higher metal-oxygen bond strength is considered to be a viable strategy to stabilize the layered structure upon extended electrochemical cycling, hereby decreasing voltage fade. The influence of Sn4+ on the voltage fade in partially charged LMR-NMC is not yet reported in the literature, and therefore, we have investigated the structure and the corresponding electrochemical properties of LMR-NMC with different Sn concentrations. We determined the substitution limit of Sn4+ in Li1.2Ni0.13Co0.13Mn0.54-xSnxO2 by powder X-ray diffraction and transmission electron microscopy to be x approximate to 0.045. The limited solubility of Sn is subsequently confirmed by density functional theory calculations. Voltage fade for x= 0 andx= 0.027 has been comparatively assessed within the 3.00 V-4.55 V (vs.Li/Li+) potential window, from which it is concluded that replacing Mn4+ by Sn4+ cannot be considered as a viable strategy to inhibit voltage fade within this window, at least with the given restricted doping level. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000555330900018 |
Publication Date |
2020-07-09 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0300-9246; 1477-9226; 1472-7773 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4 |
Times cited |
|
Open Access |
OpenAccess |
| Notes |
; The authors acknowledge Research Foundation Flanders (FWO) project number G040116N for funding. The authors are grateful to Dr Ken Elen and Greet Cuyvers (imo-imomec, UHasselt and imec) for respectively preliminary PXRD measurements and performing ICP-AES on the monometal precursors. Dr Dmitry Rupasov (Skolkovo Institute of Science and Technology) is acknowledged for performing TGA measurements on the metal sulfate precursors. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the FWO-Vlaanderen and the Flemish Government-department EWI. ; |
Approved |
Most recent IF: 4; 2020 IF: 4.029 |
| Call Number |
UA @ admin @ c:irua:171149 |
Serial |
6450 |
| Permanent link to this record |
