| |
Records |
Links |
|
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 |
Adam, N.; Leroux, F.; Knapen, D.; Bals, S.; Blust, R. |
|
| |
Title |
The uptake of ZnO and CuO nanoparticles in the water-flea Daphnia magna under acute exposure scenarios |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Environmental pollution |
Abbreviated Journal |
Environ Pollut |
|
| |
Volume |
194 |
Issue |
|
Pages |
130-137 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Veterinary physiology and biochemistry |
|
| |
Abstract |
In this study the uptake of ZnO and CuO nanoparticles by Daphnia magna was tested. Daphnids were exposed during 48 h to acute concentrations of the nanoparticles and corresponding metal salts. The Daphnia zinc and copper concentration was measured and the nanoparticles were localized using electron microscopy. The aggregation and dissolution in the medium was characterized. A fast dissolution of ZnO in the medium was observed, while most CuO formed large aggregates and only a small fraction dissolved. The Daphnia zinc concentration was comparable for the nanoparticles and salts. Contrarily, a much higher Daphnia copper concentration was observed in the CuO exposure, compared to the copper salt. CuO nanoparticles adsorbed onto the carapace and occurred in the gut but did not internalize in the tissues. The combined dissolution and uptake results indicate that the toxicity of both nanoparticle types was caused by metal ions dissolved from the particles in the medium. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
London |
Editor |
|
|
| |
Language |
|
Wos |
000342530800016 |
Publication Date |
2014-08-07 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0269-7491; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
5.099 |
Times cited |
45 |
Open Access |
Not_Open_Access |
|
| |
Notes |
; We would like to thank Valentine Mubiana and Steven Joosen (Sphere, UA) for performing the ICP-OES and ICP-MS measurements and Prof. Dr. Gustaaf Van Tendeloo for making the collaboration between the EMAT and Sphere group possible. Additional thanks go to the European Commission for funding this work through the project ENNSATOX (NMP4-SL-2009-229244). ; |
Approved |
Most recent IF: 5.099; 2014 IF: 4.143 |
|
| |
Call Number |
UA @ lucian @ c:irua:118326 |
Serial |
3823 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Kim, Y.; Che, F.; Jo, J.W.; Choi, J.; de Arquer, F.P.G.; Voznyy, O.; Sun, B.; Kim, J.; Choi, M.-J.; Quintero-Bermudez, R.; Fan, F.; Tan, C.S.; Bladt, E.; Walters, G.; Proppe, A.H.; Zou, C.; Yuan, H.; Bals, S.; Hofkens, J.; Roeffaers, M.B.J.; Hoogland, S.; Sargent, E.H. |
|
| |
Title |
A Facet-Specific Quantum Dot Passivation Strategy for Colloid Management and Efficient Infrared Photovoltaics |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Advanced materials |
Abbreviated Journal |
Adv Mater |
|
| |
Volume |
31 |
Issue |
31 |
Pages |
1805580 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
Colloidal nanocrystals combine size- and facet-dependent properties with solution processing. They offer thus a compelling suite of materials for technological applications. Their size- and facet-tunable features are studied in synthesis; however, to exploit their features in optoelectronic devices, it will be essential to translate control over size and facets from the colloid all the way to the film. Larger-diameter colloidal quantum dots (CQDs) offer the attractive possibility of harvesting infrared (IR) solar energy beyond absorption of silicon photovoltaics. These CQDs exhibit facets (nonpolar (100)) undisplayed in small-diameter CQDs; and the materials chemistry of smaller nanocrystals fails consequently to translate to materials for the short-wavelength IR regime. A new colloidal management strategy targeting the passivation of both (100) and (111) facets is demonstrated using distinct choices of cations and anions. The approach leads to narrow-bandgap CQDs with impressive colloidal stability and photoluminescence quantum yield. Photophysical studies confirm a reduction both in Stokes shift (approximate to 47 meV) and Urbach tail (approximate to 29 meV). This approach provides a approximate to 50% increase in the power conversion efficiency of IR photovoltaics compared to controls, and a approximate to 70% external quantum efficiency at their excitonic peak. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000465600000001 |
Publication Date |
2019-03-12 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0935-9648 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
19.791 |
Times cited |
74 |
Open Access |
OpenAccess |
|
| |
Notes |
; Y.K., F.C., J.W.J., and J.C. contributed equally. This work was supported by King Abdullah University of Science and Technology (KAUST, Office of Sponsored Research (OSR), Award No. OSR-2017-CPF-3325) and Ontario Research Fund-Research Excellence program (ORF7-Ministry of Research and Innovation, Ontario Research Fund-Research Excellence Round 7). E.B. gratefully acknowledges financial support by the Research Foundation-Flanders (FWO Vlaanderen). Y.K. received financial support from the DGIST R&D Programs of the Ministry of Science, ICT & Future Planning of Korea (18-ET-01). M.B.J.R. and J.H. acknowledge financial support from the Research Foundation-Flanders (FWO, grants nr ZW15_09-GOH6316 and G.098319N) and the Flemish government through long-term structural funding Methusalem (CASAS2, Meth/15/04). H.Y. acknowledges the Research Foundation-Flanders (FWO) for a postdoctoral fellowship. The authors thank L. Levina, R. Wolowiec, D. Kopilovic, and E. Palmiano for their technical help over the course of this research. ; |
Approved |
Most recent IF: 19.791 |
|
| |
Call Number |
UA @ admin @ c:irua:160392 |
Serial |
5239 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Zhang, G.; Zhou, Y.; Korneychuk, S.; Samuely, T.; Liu, L.; May, P.W.; Xu, Z.; Onufriienko, O.; Zhang, X.; Verbeeck, J.; Samuely, P.; Moshchalkov, V.V.; Yang, Z.; Rubahn, H.-G. |
|
| |
Title |
Superconductor-insulator transition driven by pressure-tuned intergrain coupling in nanodiamond films |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Physical review materials |
Abbreviated Journal |
|
|
| |
Volume |
3 |
Issue |
3 |
Pages |
034801 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
We report on the pressure-driven superconductor-insulator transition in heavily boron-doped nanodiamond films. By systematically increasing the pressure, we suppress the Josephson coupling between the superconducting nanodiamond grains. The diminished intergrain coupling gives rise to an overall insulating state in the films, which is interpreted in the framework of a parallel-series circuit model to be the result of bosonic insulators with preserved localized intragrain superconducting order parameters. Our investigation opens up perspectives for the application of high pressure in research on quantum confinement and coherence. Our data unveil the percolative nature of the electrical transport in nanodiamond films, and highlight the essential role of grain boundaries in determining the electronic properties of this material. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000460684600002 |
Publication Date |
2019-03-05 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2475-9953 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.926 |
Times cited |
5 |
Open Access |
Not_Open_Access |
|
| |
Notes |
; Y.Z. and Z.Y. acknowledge support from the National Key Research and Development Program of China (Grants No. 2018YFA0305700 and No. 2016YFA0401804), the National Natural Science Foundation of China (Grants No. 11574323, No. 11704387, and No. U1632275), the Natural Science Foundation of Anhui Province (Grants No. 1708085QA19 and No. 1808085MA06), and the Director's Fund of Hefei Institutes of Physical Science, Chinese Academy of Sciences (YZJJ201621). J.V. and S.K. acknowledge funding from the GOA project “Solarpaint” of the University of Antwerp, and thank the FWO (Research Foundation-Flanders) for financial support under Contract No. G.0044.13N “Charge ordering”. The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. T.S., O.O., and P.S. are supported by APVV-0036-11, APVV-0605-14, VEGA 1/0409/15, VEGA 2/0149/16, and EU ERDF-ITMS 26220120005. L.L. acknowledges the financial support of a FWO postdoctoral research fellowship (12V4419N) and the KU Leuven C1 project OPTIPROBE (C14/16/ 063). ; |
Approved |
Most recent IF: NA |
|
| |
Call Number |
UA @ admin @ c:irua:158561 |
Serial |
5260 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Li, W.; Hu, Z.-Y.; Zhang, Z.; Wei, P.; Zhang, J.; Pu, Z.; Zhu, J.; He, D.; Mu, S.; Van Tendeloo, G. |
|
| |
Title |
Nano-single crystal coalesced PtCu nanospheres as robust bifunctional catalyst for hydrogen evolution and oxygen reduction reactions |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Journal of catalysis |
Abbreviated Journal |
J Catal |
|
| |
Volume |
375 |
Issue |
375 |
Pages |
164-170 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
Because of high electrocatalytic activity, Pt based metal nanospheres (NSs) have attracted a lot of attention. Hence, multi-particle nano-single crystal coalesced PtCu NSs are designed and successfully synthesized by a cost-effective aqueous solution method. The formed PtCu NS catalyst exhibits a superior hydrogen evolution reaction (HER) electrocatalytic activity with an ultralow onset potential of 18 mV at the current density of 2 mA/cm(2) and high mass activity of 1.08 A/mg(pt) (7.2 times higher than that of commercial Pt/C catalysts). Also, it shows an enhancement of 3.2 and 2.7 times in the mass and specific activities toward oxygen reduction reaction (ORR) compared to that of Pt/C. Moreover, it possesses an excellent catalytic durability for both ORR and HER. Even after 10,000 cycles, its ORR mass activity retains 87% of its initial value. The density functional theory (DFT) calculations demonstrate that by introducing Cu atoms into the Pt lattice, a downshift of the D-band center and favorable hydrogen adsorption free energy of approaching to zero (Delta G) occur, indicating the increased electrocatalytic activity of Pt electrocatalysts. (C) 2019 Elsevier Inc. All rights reserved. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000486104500017 |
Publication Date |
2019-06-13 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0021-9517 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
6.844 |
Times cited |
25 |
Open Access |
|
|
| |
Notes |
; Z-Y. Hu thank for the support of “the Fundamental Research Funds for the Central Universities (WUT: 2017111055, 2018111039GX, 2018IVA095)”. S. Mu and J. Zhang acknowledges the support from the National Natural Science Foundation of China (NSFC) through award Nos. 51672204 and 21875221 and the opening funds of State Key Laboratory of Advanced Technology for Materials Synthesis and Processing (2019-KF-13), Wuhan University of Technology. ; |
Approved |
Most recent IF: 6.844 |
|
| |
Call Number |
UA @ admin @ c:irua:162903 |
Serial |
5391 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Ren, Z.; Wu, M.; Chen, X.; Li, W.; Li, M.; Wang, F.; Tian, H.; Chen, J.; Xie, Y.; Mai, J.; Li, X.; Lu, X.; Lu, Y.; Zhang, H.; Van Tendeloo, G.; Zhang, Z.; Han, G. |
|
| |
Title |
Electrostatic force-driven oxide heteroepitaxy for interface control |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Advanced materials |
Abbreviated Journal |
Adv Mater |
|
| |
Volume |
30 |
Issue |
38 |
Pages |
1707017 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
Oxide heterostructure interfaces create a platform to induce intriguing electric and magnetic functionalities for possible future devices. A general approach to control growth and interface structure of oxide heterostructures will offer a great opportunity for understanding and manipulating the functionalities. Here, it is reported that an electrostatic force, originating from a polar ferroelectric surface, can be used to drive oxide heteroepitaxy, giving rise to an atomically sharp and coherent interface by using a low-temperature solution method. These heterostructures adopt a fascinating selective growth, and show a saturation thickness and the reconstructed interface with concentrated charges accumulation. The ferroelectric polarization screening, developing from a solid-liquid interface to the heterostructure interface, is decisive for the specific growth. At the interface, a charge transfer and accumulation take place for electrical compensation. The facile approach presented here can be extremely useful for controlling oxide heteroepitaxy and producing intriguing interface functionality via electrostatic engineering. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
|
| |
Language |
|
Wos |
000444671900002 |
Publication Date |
2018-08-07 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0935-9648 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
19.791 |
Times cited |
4 |
Open Access |
Not_Open_Access |
|
| |
Notes |
; Z.H.R., M.J.W., and X.C. contributed equally to this work. This work was financially supported by the National Natural Science Foundation of China (Grant Nos. 51232006, 51472218, 11474249, 61574123, 11374009, and 11234011), the National 973 Program of China (Grant No. 2015CB654901), National Young 1000 Talents Program of China, the Fundamental Research Funds for the Central Universities (Grant No. 2017FZA4008), and the 111 Project under Grant No. B16042. J.M. and X.L. gratefully thank the beam time and technical supports provided by 23A SWAXS beamline at NSRRC, Hsinchu. ; |
Approved |
Most recent IF: 19.791 |
|
| |
Call Number |
UA @ lucian @ c:irua:153628 |
Serial |
5098 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Dixit, H.; Saniz, R.; Lamoen, D.; Partoens, B. |
|
| |
Title |
Accurate pseudopotential description of the GW bandstructure of ZnO |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Computer physics communications |
Abbreviated Journal |
Comput Phys Commun |
|
| |
Volume |
182 |
Issue |
9 |
Pages |
2029-2031 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
|
| |
Abstract |
We present the GW band structure of ZnO in its wurtzite (WZ), zincblende (ZB) and rocksalt (RS) phases at the Γ point, calculated within the GW approximation. We have used a Zn20+ pseudopotential which is essential for the adequate treatment of the exchange interaction in the self-energy. The accuracy of the pseudopotential used is also discussed. The effect of the pd hybridization on the GW corrections to the band gap is correlated by comparing the ZB and RS phase. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
|
| |
Language |
|
Wos |
000292675100062 |
Publication Date |
2011-02-17 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0010-4655; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.936 |
Times cited |
18 |
Open Access |
|
|
| |
Notes |
; ; |
Approved |
Most recent IF: 3.936; 2011 IF: 3.268 |
|
| |
Call Number |
UA @ lucian @ c:irua:90761 |
Serial |
51 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Dixit, H.; Tandon, N.; Cottenier, S.; Saniz, R.; Lamoen, D.; Partoens, B. |
|
| |
Title |
Erratum : First-principles study of possible shallow donors in ZnAl2O4 spinel [Phys. Rev. B 87, 174101 (2013)] |
Type |
A1 Journal article |
| |
Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
|
| |
Volume |
88 |
Issue |
5 |
Pages |
059905-2 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
|
| |
Abstract |
|
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000323572600009 |
Publication Date |
2013-08-27 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.836 |
Times cited |
1 |
Open Access |
|
|
| |
Notes |
; ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
|
| |
Call Number |
UA @ lucian @ c:irua:110015 |
Serial |
1080 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Lobato, I.; Partoens, B. |
|
| |
Title |
Multiple Dirac particles in AA-stacked graphite and multilayers of graphene |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
|
| |
Volume |
83 |
Issue |
16 |
Pages |
165429-165429,9 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
|
| |
Abstract |
Using the tight-binding formalism we show that in the recently experimentally realized AA-stacked graphite in essence two types of massless relativistic Dirac particles are present with a different effective speed of light. We also investigate how the electronic structure evolves from a single graphene sheet into AA-stacked graphite. It is shown that in contrast to AB-stacked graphene layers, the spectrum of AA-stacked graphene layers can be considered as a superposition of single-layer spectra and only particles with a linear spectrum at the Fermi energy around the K point are present. From the evolution of the band overlap we show that 6 multilayers of AA-stacked graphene already behave as AA-stacked graphite. The evolution of the effective speeds of light of the Dirac particles to their bulk values shows exactly the same behavior. The tight-binding parameters we use to describe AA-stacked graphite and multilayers of graphene are obtained by ab initio calculations. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000290113900005 |
Publication Date |
2011-04-21 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.836 |
Times cited |
68 |
Open Access |
|
|
| |
Notes |
; ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
|
| |
Call Number |
UA @ lucian @ c:irua:89717 |
Serial |
2225 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Liz-Marzan, L.; Bals, S. |
|
| |
Title |
Advanced particle characterization techniques |
Type |
Editorial |
| |
Year |
2016 |
Publication |
Particle and particle systems characterization |
Abbreviated Journal |
Part Part Syst Char |
|
| |
Volume |
33 |
Issue |
33 |
Pages |
350-351 |
|
| |
Keywords |
Editorial; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
|
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Wiley-v c h verlag gmbh |
Place of Publication |
Weinheim |
Editor |
|
|
| |
Language |
|
Wos |
000379970000001 |
Publication Date |
2016-07-14 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0934-0866 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
|
| |
Impact Factor |
4.474 |
Times cited |
|
Open Access |
Not_Open_Access |
|
| |
Notes |
; ; |
Approved |
Most recent IF: 4.474 |
|
| |
Call Number |
UA @ lucian @ c:irua:134957 |
Serial |
4136 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Janssens, K.; van der Snickt, G.; Vanmeert, F.; Legrand, S.; Nuyts, G.; Alfeld, M.; Monico, L.; Anaf, W.; de Nolf, W.; Vermeulen, M.; Verbeeck, J.; De Wael, K. |
|
| |
Title |
Non-invasive and non-destructive examination of artistic pigments, paints, and paintings by means of X-Ray methods |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Topics in Current Chemistry |
Abbreviated Journal |
Topics Curr Chem |
|
| |
Volume |
374 |
Issue |
374 |
Pages |
81 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
|
| |
Abstract |
Recent studies are concisely reviewed, in which X-ray beams of (sub)micrometre to millimetre dimensions have been used for non-destructive analysis and characterization of pigments, minute paint samples, and/or entire paintings from the seventeenth to the early twentieth century painters. The overview presented encompasses the use of laboratory and synchrotron radiation-based instrumentation and deals with the use of several variants of X-ray fluorescence (XRF) as a method of elemental analysis and imaging, as well as with the combined use of X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS). Microscopic XRF is a variant of the method that is well suited to visualize the elemental distribution of key elements, mostly metals, present in paint multi-layers, on the length scale from 1 to 100 μm inside micro-samples taken from paintings. In the context of the characterization of artists pigments subjected to natural degradation, the use of methods limited to elemental analysis or imaging usually is not sufficient to elucidate the chemical transformations that have taken place. However, at synchrotron facilities, combinations of μ-XRF with related methods such as μ-XAS and μ-XRD have proven themselves to be very suitable for such studies. Their use is often combined with microscopic Fourier transform infra-red spectroscopy and/or Raman microscopy since these methods deliver complementary information of high molecular specificity at more or less the same length scale as the X-ray microprobe techniques. Since microscopic investigation of a relatively limited number of minute paint samples, taken from a given work of art, may not yield representative information about the entire artefact, several methods for macroscopic, non-invasive imaging have recently been developed. Those based on XRF scanning and full-field hyperspectral imaging appear very promising; some recent published results are discussed. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Springer international publishing ag |
Place of Publication |
Cham |
Editor |
|
|
| |
Language |
|
Wos |
000391178900006 |
Publication Date |
2016-11-21 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2365-0869;2364-8961; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.033 |
Times cited |
50 |
Open Access |
|
|
| |
Notes |
; ; |
Approved |
Most recent IF: 4.033 |
|
| |
Call Number |
UA @ lucian @ c:irua:139930UA @ admin @ c:irua:139930 |
Serial |
4443 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Van Eynde, E.; Hu, Z.-Y.; Tytgat, T.; Verbruggen, S.W.; Watte, J.; Van Tendeloo, G.; Van Driessche, I.; Blust, R.; Lenaerts, S. |
|
| |
Title |
Diatom silica-titania photocatalysts for air purification by bio-accumulation of different titanium sources |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Environmental science : nano |
Abbreviated Journal |
Environ Sci-Nano |
|
| |
Volume |
3 |
Issue |
5 |
Pages |
1052-1061 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Sustainable Energy, Air and Water Technology (DuEL) |
|
| |
Abstract |
We present a green, biological production route for silica-titania photocatalysts using diatom microalgae. Diatoms are single-celled, eukaryotic microalgae (2-2000 mu m) that self-assemble soluble silicon (Si(OH)(4)) into intricate silica cell walls, called frustules. These diatom frustules are formed under ambient conditions and consist of hydrated silica with specific 3D morphologies and micro-meso or macroporosity. A remarkable characteristic of diatoms is their ability to bioaccumulate soluble titanium from cell culture medium and incorporate them into their nanostructured silica cell wall. Controlled cultivation of the diatom Pinnularia sp. on soluble titanium in a batch process resulted in the biological immobilisation of titanium dioxide in the porous 3D architecture of the frustules. Six different titanium sources are tested. The silica-titania frustules were isolated by treating the harvested Pinnularia cells with nitric acid (65%) or by high temperature treatment. Thermal annealing converted the amorphous titania into crystalline titania. The produced silica-titania material is evaluated towards photocatalytic activity for acetaldehyde (C2H4O) abatement. Frustules cultivated with TiBaldH showed the highest photocatalytic performance. Comparison of the photocatalytic activity with P25 reveals that P25 has a 4 fold higher photocatalytic activity, but when photocatalytic activity is normalized for titania content, the frustules show double activity. Further material characterization (morphology, crystallinity, surface area and elemental distribution) of the TiBaldH silica-titania frustules provides additional insight into their structure-activity relationship. These natural biosilicatitania materials have excellent properties for photocatalytic purposes, including high surface area (108 m(2) g(-1)) and good porosity, and show reliable immobilization of TiO2 in the ordered structure of the diatom frustule. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Royal Society of Chemistry |
Place of Publication |
Cambridge |
Editor |
|
|
| |
Language |
|
Wos |
000385257900011 |
Publication Date |
2016-07-21 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2051-8153; 2051-8161 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
6.047 |
Times cited |
7 |
Open Access |
|
|
| |
Notes |
; ; |
Approved |
Most recent IF: 6.047 |
|
| |
Call Number |
UA @ lucian @ c:irua:144751 |
Serial |
4644 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Longo, R.; Ferrarotti, M.; Garcia Sánchez, C.; Derudi, M.; Parente, A. |
|
| |
Title |
Advanced turbulence models and boundary conditions for flows around different configurations of ground-mounted buildings |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Journal of wind engineering and industrial aerodynamics |
Abbreviated Journal |
J Wind Eng Ind Aerod |
|
| |
Volume |
167 |
Issue |
|
Pages |
160-182 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
When dealing with Atmospheric Boundary Layer (ABL) simulations, commercial computational fluid dynamics (CFD) acquires a strategic resonance. Thanks to its good compromise between accuracy of results and calculation time, RANS still represents a valid alternative to more resource-demanding methods. However, focusing on the models' performances in urban studies, LES generally outmatches RANS results, even if the former is at least one order of magnitude more expensive. Consequently, the present work aims to propose a variety of approaches meant to solve some of the major problems linked to RANS simulations and to further improve its accuracy in typical urban contexts. All of these models are capable of switching from an undisturbed flux formulation to a disturbed one through a local deviation or a marker function. For undisturbed flows, a comprehensive approach is adopted, solving the issue of the erroneous stream-wise gradients affecting the turbulent profiles. Around obstacles, Non-Linear Eddy-Viscosity closures are adopted, due to their prominent capability in capturing the anisotropy of turbulence. The purpose of this work is then to propose a new Building Influence Area concept and to offer more affordable alternatives to LES simulations without sacrificing a good grade of accuracy. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
|
| |
Language |
|
Wos |
000405766600013 |
Publication Date |
2017-05-02 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0167-6105 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.049 |
Times cited |
9 |
Open Access |
Not_Open_Access |
|
| |
Notes |
; ; |
Approved |
Most recent IF: 2.049 |
|
| |
Call Number |
UA @ lucian @ c:irua:145191 |
Serial |
4713 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Cautaerts, N.; Delville, R.; Dietz, W.; Verwerft, M. |
|
| |
Title |
Thermal creep properties of Ti-stabilized DIN 1.4970 (15-15Ti) austenitic stainless steel pressurized cladding tubes |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Journal of nuclear materials |
Abbreviated Journal |
J Nucl Mater |
|
| |
Volume |
493 |
Issue |
|
Pages |
154-167 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
This paper presents a large database of thermal creep data from pressurized unirradiated DIN 1.4970 Ti-stabilized austenitic stainless steel (i.e. EN 1515CrNiMoTiB or “15-15Ti”) cladding tubes from more than 1000 bi-axial creep tests conducted during the fast reactor R&D program of the DeBeNe (Deutschland-Belgium- Netherlands) consortium between the 1960's to the late 1980's. The data comprises creep rate and time-to-rupture between 600 and 750 degrees C and a large range of stresses. The data spans tests on material from around 70 different heats and 30 different melts. Around one fourth of the data was obtained from cold worked material, the rest was obtained on cold worked + aged (800 degrees C, 2 h) material. The data are graphically presented in log-log graphs. The creep rate data is fit with a sinh correlation, the time to rupture data is fit with a modified exponential function through the Larson-Miller parameter. Local equivalent parameters to Norton's law are calculated and compared to literature values for these types of steels and related to possible creep mechanisms. Some time to rupture data above 950 degrees C is compared to literature dynamic recrystallization data. Time to rupture data between 600 and 750 degrees C is also compared to literature data from 316 steel. Time to rupture was correlated directly to creep rate with the Monkman-Grant relationship at different temperatures. (C) 2017 Elsevier B.V. All rights reserved. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
|
| |
Language |
|
Wos |
000408044000018 |
Publication Date |
2017-06-11 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0022-3115 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.048 |
Times cited |
5 |
Open Access |
OpenAccess |
|
| |
Notes |
; ; |
Approved |
Most recent IF: 2.048 |
|
| |
Call Number |
UA @ lucian @ c:irua:145686 |
Serial |
4753 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Choudhary, K.; Bercx, M.; Jiang, J.; Pachter, R.; Lamoen, D.; Tavazza, F. |
|
| |
Title |
Accelerated Discovery of Efficient Solar Cell Materials Using Quantum and Machine-Learning Methods |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
|
| |
Volume |
31 |
Issue |
15 |
Pages |
5900-5908 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
Solar energy plays an important role in solving serious environmental
problems and meeting the high energy demand. However, the lack of suitable
materials hinders further progress of this technology. Here, we present the largest
inorganic solar cell material search till date using density functional theory (DFT) and
machine-learning approaches. We calculated the spectroscopic limited maximum
efficiency (SLME) using the Tran−Blaha-modified Becke−Johnson potential for 5097
nonmetallic materials and identified 1997 candidates with an SLME higher than 10%,
including 934 candidates with a suitable convex-hull stability and an effective carrier
mass. Screening for two-dimensional-layered cases, we found 58 potential materials
and performed G0W0 calculations on a subset to estimate the prediction uncertainty. As the above DFT methods are still computationally expensive, we developed a high accuracy machine-learning model to prescreen efficient materials and applied it to over a million materials. Our results provide a general framework and universal strategy for the design of high-efficiency solar
cell materials. The data and tools are publicly distributed at: https://www.ctcms.nist.gov/~knc6/JVASP.html, https://www.
ctcms.nist.gov/jarvisml/, https://jarvis.nist.gov/, and https://github.com/usnistgov/jarvis. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000480826900060 |
Publication Date |
2019-08-13 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0897-4756 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
9.466 |
Times cited |
6 |
Open Access |
|
|
| |
Notes |
; ; |
Approved |
Most recent IF: 9.466 |
|
| |
Call Number |
EMAT @ emat @c:irua:161814 |
Serial |
5291 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
De Beule, C.; Saniz, R.; Partoens, B. |
|
| |
Title |
Crystalline topological states at a topological insulator junction |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
The journal of physics and chemistry of solids |
Abbreviated Journal |
J Phys Chem Solids |
|
| |
Volume |
128 |
Issue |
128 |
Pages |
144-151 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
|
| |
Abstract |
We consider an interface between two strong time-reversal invariant topological insulators having surface states with opposite spin chirality, or equivalently, opposite mirror Chern number. We show that such an interface supports gapless modes that are protected by mirror symmetry. The interface states are investigated with a continuum model for the Bi2Se3 class of topological insulators that takes into account terms up to third order in the crystal momentum, which ensures that the model has the correct symmetry. The model parameters are obtained from ab initio calculations. Finally, we consider the effect of rotational mismatch at the interface, which breaks the mirror symmetry and opens a gap in the interface spectrum. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000472693100013 |
Publication Date |
2018-01-31 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0022-3697 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
|
| |
Impact Factor |
2.059 |
Times cited |
|
Open Access |
|
|
| |
Notes |
; ; |
Approved |
Most recent IF: 2.059 |
|
| |
Call Number |
UA @ admin @ c:irua:161391 |
Serial |
5385 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Hadermann, J.; Palatinus, L. |
|
| |
Title |
Introducton to the special issue on electron crystallography |
Type |
Editorial |
| |
Year |
2019 |
Publication |
And Materials |
Abbreviated Journal |
|
|
| |
Volume |
75 |
Issue |
4 |
Pages |
462-462 |
|
| |
Keywords |
Editorial; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
|
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000480512600028 |
Publication Date |
2019-08-05 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
|
Times cited |
2 |
Open Access |
|
|
| |
Notes |
; ; |
Approved |
Most recent IF: NA |
|
| |
Call Number |
UA @ admin @ c:irua:161845 |
Serial |
5389 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Liu, P.; Wu, T.; Madsen, J.; Schiotz, J.; Wagner, J.B.; Hansen, T.W. |
|
| |
Title |
Transformations of supported gold nanoparticles observed by in situ electron microscopy |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
|
| |
Volume |
11 |
Issue |
24 |
Pages |
11885-11891 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
Oxide supported metal nanoparticles play an important role in heterogeneous catalysis. However, understanding the metal/oxide interface and their evolution under reaction conditions remains challenging. Herein, we investigate the interface between Au nanoparticles and a CeO2 substrate by environmental transmission electron microscopy with atomic resolution. We find that the Au nanoparticles have two preferential epitaxial relationships with the substrate, i.e. Type I (111)[-110]CeO2//(111)[-110]Au and Type II (111)[-110]CeO2//(111)[1-10]Au orientation relationships, where Type I is preferred. In situ observations in the presence of O-2 show that the gas can stimulate the supported Au nanoparticles to transform between these two orientations even at room temperature. Moreover, when increasing the temperature to 973 K, the transformation of an Au nanoparticle between the two orientation states and a non-crystalline state in the presence of O-2 is also observed. DFT calculations of the binding between Au and CeO2 in the two relationships are strongly influenced by the presence of oxygen vacancies. For a given position of a vacancy, there is a significant energy difference between the energy of the two types. However, for some positions, Type I is preferred, and for others, Type II, but the most favourable position of the vacancy for the two types has a very similar energy. This is consistent with the observation of both types of adhesion. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000472559800049 |
Publication Date |
2019-05-22 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2040-3364 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
7.367 |
Times cited |
1 |
Open Access |
|
|
| |
Notes |
; ; |
Approved |
Most recent IF: 7.367 |
|
| |
Call Number |
UA @ admin @ c:irua:161313 |
Serial |
5402 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Cautaerts, N.; Lamm, S.; Stergar, E.; Pakarinen, J.; Yang, Y.; Hofer, C.; Schnitzer, R.; Felfer, P.; Verwerft, M.; Delville, R.; Schryvers, D. |
|
| |
Title |
Atom probe tomography data collection from DIN 1.4970 (15-15Ti) austenitic stainless steel irradiated with Fe ions |
Type |
Dataset |
| |
Year |
2020 |
Publication |
|
Abbreviated Journal |
|
|
| |
Volume |
|
Issue |
|
Pages |
|
|
| |
Keywords |
Dataset; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
This dataset comprises a large collection of atom probe tomography datasets collected from DIN 1.4970 alloy that was irradiated with Fe ions at different conditions. The DIN 1.4970 alloy is an austenitic stainless steel with 15 wt% Cr, 15 wt% Ni, a small addition of Ti. The full composition and characterization of our material can be found published elsewhere [1,2]. Some of our material was subjected to ageing heat treatments at different temperatures for different times. Small samples of our original material and aged material was irradiated at the Michigan Ion Beam Laboratory in 2017 with 4.5 MeV Fe ions up to 40 dpa at an average dose rate of 2×10−4 dpa/s. This was done at three different temperatures: 300, 450, and 600 ºC. Atom probe samples were made of the irradiated layers (approximately 1.5 micron deep) with focused ion beam and mounted on Microtip coupons. APT measurements took place on three CAMECA LEAP-HR systems located at CAES in Idaho Falls, USA (files beginning with R33), at Montanuniversität Leoben in Leoben, Austria (R21) and at Friedrich–Alexander University in Erlangen, Germany (R56). |
|
| |
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 |
Not_Open_Access |
|
| |
Notes |
; ; |
Approved |
Most recent IF: NA |
|
| |
Call Number |
UA @ admin @ c:irua:169127 |
Serial |
6454 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Mao, J.; Milovanović, S.P.; Andelkovic, M.; Lai, X.; Cao, Y.; Watanabe, K.; Taniguchi, T.; Covaci, L.; Peeters, F.M.; Geim, A.K.; Jiang, Y.; Andrei, E.Y. |
|
| |
Title |
Evidence of flat bands and correlated states in buckled graphene superlattices |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Nature |
Abbreviated Journal |
Nature |
|
| |
Volume |
584 |
Issue |
7820 |
Pages |
215-220 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
|
| |
Abstract |
Two-dimensional atomic crystals can radically change their properties in response to external influences, such as substrate orientation or strain, forming materials with novel electronic structure(1-5). An example is the creation of weakly dispersive, 'flat' bands in bilayer graphene for certain 'magic' angles of twist between the orientations of the two layers(6). The quenched kinetic energy in these flat bands promotes electron-electron interactions and facilitates the emergence of strongly correlated phases, such as superconductivity and correlated insulators. However, the very accurate fine-tuning required to obtain the magic angle in twisted-bilayer graphene poses challenges to fabrication and scalability. Here we present an alternative route to creating flat bands that does not involve fine-tuning. Using scanning tunnelling microscopy and spectroscopy, together with numerical simulations, we demonstrate that graphene monolayers placed on an atomically flat substrate can be forced to undergo a buckling transition(7-9), resulting in a periodically modulated pseudo-magnetic field(10-14), which in turn creates a 'post-graphene' material with flat electronic bands. When we introduce the Fermi level into these flat bands using electrostatic doping, we observe a pseudogap-like depletion in the density of states, which signals the emergence of a correlated state(15-17). This buckling of two-dimensional crystals offers a strategy for creating other superlattice systems and, in particular, for exploring interaction phenomena characteristic of flat bands. Buckled monolayer graphene superlattices are found to provide an alternative to twisted bilayer graphene for the study of flat bands and correlated states in a carbon-based material. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000559831500012 |
Publication Date |
2020-08-12 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0028-0836 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
64.8 |
Times cited |
109 |
Open Access |
Not_Open_Access |
|
| |
Notes |
; ; |
Approved |
Most recent IF: 64.8; 2020 IF: 40.137 |
|
| |
Call Number |
UA @ admin @ c:irua:171150 |
Serial |
6513 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Canossa, S.; Wuttke, S. |
|
| |
Title |
Functionalization chemistry of porous materials |
Type |
Editorial |
| |
Year |
2020 |
Publication |
Advanced Functional Materials |
Abbreviated Journal |
Adv Funct Mater |
|
| |
Volume |
30 |
Issue |
41 |
Pages |
2003875 |
|
| |
Keywords |
Editorial; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
|
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000580514700004 |
Publication Date |
2020-10-08 |
|
| |
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 |
1 |
Open Access |
OpenAccess |
|
| |
Notes |
; ; |
Approved |
Most recent IF: 19; 2020 IF: 12.124 |
|
| |
Call Number |
UA @ admin @ c:irua:173614 |
Serial |
6524 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Liu, P.; Madsen, J.; Schiotz, J.; Wagner, J.B.; Hansen, T.W. |
|
| |
Title |
Reversible and concerted atom diffusion on supported gold nanoparticles |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Journal Of Physics-materials |
Abbreviated Journal |
|
|
| |
Volume |
3 |
Issue |
2 |
Pages |
024009 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
Traditionally, direct imaging of atom diffusion is only available by scanning tunneling microscopy and field ion microscopy on geometry-constrained samples: flat surfaces for STM and needle tips for FIM. Here we show time-resolved atomic-scale HRTEM investigations of CeO2-supported Au nanoparticle surfaces to characterize the surface dynamics of atom columns on gold nanoparticles. The observed surface dynamics have been categorized into four types: layer jumping, layer gliding, re-orientation and surface reconstruction. We successfully captured atoms moving in a concerted manner with a time resolution of 0.1 s. A quantitative approach for measuring the dynamics in various gaseous surroundings at elevated temperatures is presented. An approach for measuring quantitative electron beam effects on the surface dynamics is presented by counting atom column occupation as a function of time under a range of dose rates in high vacuum. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000560432800009 |
Publication Date |
2020-03-24 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
|
Times cited |
2 |
Open Access |
OpenAccess |
|
| |
Notes |
; ; |
Approved |
Most recent IF: NA |
|
| |
Call Number |
UA @ admin @ c:irua:171320 |
Serial |
6597 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Annys, A.; Jannis, D.; Verbeeck, J.; Annys, A.; Jannis, D.; Verbeeck, J. |
|
| |
Title |
Deep learning for automated materials characterisation in core-loss electron energy loss spectroscopy |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Scientific reports |
Abbreviated Journal |
|
|
| |
Volume |
13 |
Issue |
1 |
Pages |
13724 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
Electron energy loss spectroscopy (EELS) is a well established technique in electron microscopy that yields information on the elemental content of a sample in a very direct manner. One of the persisting limitations of EELS is the requirement for manual identification of core-loss edges and their corresponding elements. This can be especially bothersome in spectrum imaging, where a large amount of spectra are recorded when spatially scanning over a sample area. This paper introduces a synthetic dataset with 736,000 labeled EELS spectra, computed from available generalized oscillator strength tables, that represents 107 K, L, M or N core-loss edges and 80 chemical elements. Generic lifetime broadened peaks are used to mimic the fine structure due to band structure effects present in experimental core-loss edges. The proposed dataset is used to train and evaluate a series of neural network architectures, being a multilayer perceptron, a convolutional neural network, a U-Net, a residual neural network, a vision transformer and a compact convolutional transformer. An ensemble of neural networks is used to further increase performance. The ensemble network is used to demonstrate fully automated elemental mapping in a spectrum image, both by directly mapping the predicted elemental content and by using the predicted content as input for a physical model-based mapping. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
001052937600046 |
Publication Date |
2023-08-22 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2045-2322 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
|
| |
Impact Factor |
4.6 |
Times cited |
|
Open Access |
OpenAccess |
|
| |
Notes |
A.A. would like to acknowledge the resources and services used in this work provided by the VSC (Flemish Supercomputer Center), funded by the Research Foundation – Flanders (FWO) and the Flemish Government. J.V. acknowledges the IMPRESS project. The IMPRESS project has received funding from the HORIZON EUROPE framework program for research and innovation under grant agreement n. 101094299. |
Approved |
Most recent IF: 4.6; 2023 IF: 4.259 |
|
| |
Call Number |
UA @ admin @ c:irua:198647 |
Serial |
8846 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Walters, A.A.; Santacana-Font, G.; Li, J.; Routabi, N.; Qin, Y.; Claes, N.; Bals, S.; Tzu-Wen Wang, J.; Al-Jamal, K.T. |
|
| |
Title |
Nanoparticle-MediatedIn SituMolecular Reprogramming of Immune Checkpoint Interactions for Cancer Immunotherapy |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Acs Nano |
Abbreviated Journal |
Acs Nano |
|
| |
Volume |
15 |
Issue |
11 |
Pages |
17549-17564 |
|
| |
Keywords |
A1 Journal article; Pharmacology. Therapy; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
Immune checkpoint blockade involves targeting immune
regulatory molecules with antibodies. Preclinically, complex multiantibody
regimes of both inhibitory and stimulatory targets are a promising
candidate for the next generation of immunotherapy. However, in this
setting, the antibody platform may be limited due to excessive toxicity
caused by off target effects as a result of systemic administration. RNA
can be used as an alternate to antibodies as it can both downregulate
immunosuppressive checkpoints (siRNA) or induce expression of
immunostimulatory checkpoints (mRNA). In this study, we demonstrate
that the combination of both siRNA and mRNA in a single
formulation can simultaneously knockdown and induce expression of
immune checkpoint targets, thereby reprogramming the tumor
microenvironment from immunosuppressive to immunostimulatory
phenotype. To achieve this, RNA constructs were synthesized and
formulated into stable nucleic acid lipid nanoparticles (SNALPs); the SNALPs produced were 140−150 nm in size with >80%
loading efficiency. SNALPs could transfect macrophages and B16F10 cells in vitro resulting in 75% knockdown of inhibitory
checkpoint (PDL1) expression and simultaneously express high levels of stimulatory checkpoint (OX40L) with minimal
toxicity. Intratumoral treatment with the proposed formulation resulted in statistically reduced tumor growth, a greater
density of CD4+ and CD8+ infiltrates in the tumor, and immune activation within tumor-draining lymph nodes. These data
suggest that a single RNA-based formulation can successfully reprogram multiple immune checkpoint interactions on a
cellular level. Such a candidate may be able to replace future immune checkpoint therapeutic regimes composed of both
stimulatory- and inhibitory-receptor-targeting antibodies. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000747115200039 |
Publication Date |
2021-11-23 |
|
| |
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 |
13.942 |
Times cited |
11 |
Open Access |
OpenAccess |
|
| |
Notes |
A.A.W. is the grateful recipient of a Maplethorpe Fellowship. K.A.J. acknowledges funding from the British Council (Newton Fund, 337313), Wellcome Trust (WT103913), and the Cancer Research UK King’s Health Partners Centre at King’s College London. Financial support is acknowledged from the European Commission under the Horizon 2020 Programme, by means of Grant Agreement No. 731019 (EUSMI). Images were drawn on BioRender.com. |
Approved |
Most recent IF: 13.942 |
|
| |
Call Number |
EMAT @ emat @c:irua:183950 |
Serial |
6829 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Béché, A.; Goris, B.; Freitag, B.; Verbeeck, J. |
|
| |
Title |
Development of a fast electromagnetic beam blanker for compressed sensing in scanning transmission electron microscopy |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
|
| |
Volume |
108 |
Issue |
108 |
Pages |
093103 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
The concept of compressed sensing was recently proposed to significantly reduce the electron dose in scanning transmission electron microscopy (STEM) while still maintaining the main features in the image. Here, an experimental setup based on an electromagnetic beam blanker placed in the condenser plane of a STEM is proposed. The beam blanker deflects the beam with a random pattern, while the scanning coils are moving the beam in the usual scan pattern. Experimental images at both the medium scale and high resolution are acquired and reconstructed based on a discrete cosine algorithm. The obtained results confirm that compressed sensing is highly attractive to limit beam damage in experimental STEM even though some remaining artifacts need to be resolved. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000375329200043 |
Publication Date |
2016-03-01 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0003-6951 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.411 |
Times cited |
40 |
Open Access |
|
|
| |
Notes |
A.B and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510 VORTEX and under a contract for an Integrated Infrastructure Initiative (Reference No. 312483 ESTEEM2), from the GOA project SOLARPAINT and the POC project I13/009 from the University of Antwerp. B.G. acknowledges the Research Foundation Flanders (FWO Vlaanderen) for a postdoctoral research grant. The QuAnTem microscope was partially funded by the Hercules Foundation. We thank Zhaoliang Liao from the Mesa+ laboratory at the University of Twente for the perovskite test sample.; esteem2jra3 ECASJO; |
Approved |
Most recent IF: 3.411 |
|
| |
Call Number |
c:irua:131895 c:irua:131895UA @ admin @ c:irua:131895 |
Serial |
4023 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Béché, A.; Winkler, R.; Plank, H.; Hofer, F.; Verbeeck, J. |
|
| |
Title |
Focused electron beam induced deposition as a tool to create electron vortices |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Micron |
Abbreviated Journal |
Micron |
|
| |
Volume |
80 |
Issue |
80 |
Pages |
34-38 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
Focused electron beam induced deposition (FEBID) is a microscopic technique that allows geometrically controlled material deposition with very high spatial resolution. This technique was used to create a spiral aperture capable of generating electron vortex beams in a transmission electron microscope (TEM). The vortex was then fully characterized using different TEM techniques, estimating the average orbital angular momentum to be approximately 0.8variant Planck's over 2pi per electron with almost 60% of the beam ending up in the l=1 state. |
|
| |
Address |
EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Wos |
000366770100006 |
Publication Date |
2015-09-12 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0968-4328; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
1.98 |
Times cited |
21 |
Open Access |
|
|
| |
Notes |
A.B and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510 VORTEX. J.V., R.W., H.P. and F.H. acknowledge financial support from the European Union under the 7th Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative (Reference No. 312483 ESTEEM2). R.W and H.P also acknowledge financial support by the COST action CELINA (Nr. CM1301) and the EUROSTARS project TRIPLE-S (Nr. E!8213). The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government.; esteem2jra3 ECASJO; |
Approved |
Most recent IF: 1.98; 2015 IF: 1.988 |
|
| |
Call Number |
c:irua:129203 c:irua:129203UA @ admin @ c:irua:129203 |
Serial |
3946 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Béché, A.; Juchtmans, R.; Verbeeck, J. |
|
| |
Title |
Efficient creation of electron vortex beams for high resolution STEM imaging |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
| |
Volume |
178 |
Issue |
178 |
Pages |
12-19 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
The recent discovery of electron vortex beams carrying quantised angular momentum in the TEM has led to an active field of research, exploring a variety of potential applications including the possibility of mapping magnetic states at the atomic scale. A prerequisite for this is the availability of atomic sized electron vortex beams at high beam current and mode purity. In this paper we present recent progress showing that by making use of the Aharonov-Bohm effect near the tip of a long single domain ferromagnetic Nickel needle, a very efficient aperture for the production of electron vortex beams can be realised. The aperture transmits more than 99% of all electrons and provides a vortex mode purity of up to 92%. Placing this aperture in the condenser plane of a state of the art Cs corrected microscope allows us to demonstrate atomic resolution HAADF STEM images with spatial resolution better than 1 Angstrom, in agreement with theoretical expectations and only slightly inferior to the performance of a non-vortex probe on the same instrument. |
|
| |
Address |
EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Wos |
000403862900003 |
Publication Date |
2016-05-10 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.843 |
Times cited |
30 |
Open Access |
OpenAccess |
|
| |
Notes |
A.B. and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510 VORTEX. J.V. acknowledges funding from FWO project G.0044.13N ('Charge ordering').; ECASJO_; |
Approved |
Most recent IF: 2.843 |
|
| |
Call Number |
c:irua:134085 c:irua:134085UA @ admin @ c:irua:134085 |
Serial |
4094 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Prabhakara, V.; Jannis, D.; Guzzinati, G.; Béché, A.; Bender, H.; Verbeeck, J. |
|
| |
Title |
HAADF-STEM block-scanning strategy for local measurement of strain at the nanoscale |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
| |
Volume |
219 |
Issue |
|
Pages |
113099 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
Lattice strain measurement of nanoscale semiconductor devices is crucial for the semiconductor industry as strain substantially improves the electrical performance of transistors. High resolution scanning transmission electron microscopy (HR-STEM) imaging is an excellent tool that provides spatial resolution at the atomic scale and strain information by applying Geometric Phase Analysis or image fitting procedures. However, HR-STEM images regularly suffer from scanning distortions and sample drift during image acquisition. In this paper, we propose a new scanning strategy that drastically reduces artefacts due to drift and scanning distortion, along with extending the field of view. It consists of the acquisition of a series of independent small subimages containing an atomic resolution image of the local lattice. All subimages are then analysed individually for strain by fitting a nonlinear model to the lattice images. The method allows flexible tuning of spatial resolution and the field of view within the limits of the dynamic range of the scan engine while maintaining atomic resolution sampling within the subimages. The obtained experimental strain maps are quantitatively benchmarked against the Bessel diffraction technique. We demonstrate that the proposed scanning strategy approaches the performance of the diffraction technique while having the advantage that it does not require specialized diffraction cameras. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000594768500006 |
Publication Date |
2020-09-01 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.2 |
Times cited |
4 |
Open Access |
OpenAccess |
|
| |
Notes |
A.B. D.J. and J.V. acknowledge funding through FWO project G093417N ('Compressed sensing enabling low dose imaging in transmission electron microscopy') from the Flanders Research Fund. J.V acknowledges funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 823717 – ESTEEM3. The Qu-Ant-EM microscope and the direct electron detector used in the diffraction experiments was partly funded by the Hercules fund from the Flemish Government. This project has received funding from the GOA project “Solarpaint” of the University of Antwerp. GG acknowledges support from a postdoctoral fellowship grant from the Fonds Wetenschappelijk Onderzoek – Vlaanderen (FWO). Special thanks to Dr. Thomas Nuytten, Prof. Dr. Wilfried Vandervorst, Dr. Paola Favia, Dr. Olivier Richard from IMEC, Leuven and Prof. Dr. Sara Bals from EMAT, Antwerp for their continuous support and collaboration with the project and to the IMEC processing group for the device fabrication. |
Approved |
Most recent IF: 2.2; 2020 IF: 2.843 |
|
| |
Call Number |
EMAT @ emat @c:irua:172485 |
Serial |
6404 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Canossa, S.; Ferrari, E.; Sippel, P.; Fischer, J.K.H.; Pfattner, R.; Frison, R.; Masino, M.; Mas-Torrent, M.; Lunkenheimer, P.; Rovira, C.; Girlando, A. |
|
| |
Title |
Tetramethylbenzidine-TetrafluoroTCNQ (TMB-TCNQF(4)) : a narrow-gap semiconducting salt with room-temperature relaxor ferroelectric behavior |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Journal Of Physical Chemistry C |
Abbreviated Journal |
J Phys Chem C |
|
| |
Volume |
125 |
Issue |
46 |
Pages |
25816-25824 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
We present an extension and revision of the spectroscopic and structural data of the mixed-stack charge-transfer (CT) crystal 3,3 ',5,5 '-tetramethylbenzidine-tetrafluorotetracyano-quinodimethane (TMB-TCNQF4), associated with new electric and dielectric measurements. Refinement of synchrotron structural data at low temperature has led to revise the previously reported C2/m structure. The revised structure is P2(1)/m, with two dimerized stacks per unit cell, and is consistent with the low temperature vibrational data. However, polarized Raman data in the low-frequency region also indicate that by increasing temperature above 200 K, the structure presents an increasing degree of disorder, mainly along the stack axis. X-ray diffraction data at room temperature have confirmed that the correct structure is P2(1)/ m -no phase transitions -but did not allow substantiating the presence of disorder. On the other hand, dielectric measurements have evidenced a typical relaxor ferroelectric behavior already at room temperature, with a peak in the real part of dielectric constant epsilon'(T,v) around 200 K and 0.1 Hz. The relaxor behavior is explained in terms of the presence of spin solitons separating domains of opposite polarity that yield to ferroelectric nanodomains. TMB-TCNQF(4) is confirmed to be a narrow-gap band semiconductor (Ea similar to 0.3 eV) with a room-temperature conductivity of similar to 10(-4) Omega(-1) cm(-1). |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000731170500008 |
Publication Date |
0000-00-00 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1932-7447; 1932-7455 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.536 |
Times cited |
|
Open Access |
Not_Open_Access |
|
| |
Notes |
A.G. thanks Prof. Pascale Foury-Leylekian for very helpful discussions about the crystallographic issues. R.F. thanks Prof. Anthony Linden for his help in the X-ray diffraction data collection. J.K.H.F. and P.L. acknowledge funding from the Deutsche Forschungsgemeinschaft (DFG) via the Transregional Collaborative Research Center TRR80 (Augsburg, Munich). R.P. and M.M.-T. acknowledge support from the Marie Curie Cofund, Beatriu de Pinós Fellowships (Grant nos. AGAUR 2017 BP 00064). This work was also supported by the Spanish Ministry project GENESIS PID2019-111682RBI00, the “Severo Ochoa” Programme for Centers of Excellence in R&D (FUNFUTURE, CEX2019-000917-S), and the Generalitat de Catalunya (2017-SGR-918). The Elettra Synchrotron (CNR Trieste) is acknowledged for granting the beamtime at the single-crystal diffraction beamline XRD1 (Proposal ID 20185483). In Parma, the work has benefited from the equipment and support of the COMP-HUB Initiative, funded by the “Departments of Excellence” program of the |
Approved |
Most recent IF: 4.536 |
|
| |
Call Number |
UA @ admin @ c:irua:184866 |
Serial |
7066 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Kirkwood, N.; De Backer, A.; Altantzis, T.; Winckelmans, N.; Longo, A.; Antolinez, F.V.; Rabouw, F.T.; De Trizio, L.; Geuchies, J.J.; Mulder, J.T.; Renaud, N.; Bals, S.; Manna, L.; Houtepen, A.J. |
|
| |
Title |
Locating and controlling the Zn content in In(Zn)P quantum dots |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
|
| |
Volume |
32 |
Issue |
32 |
Pages |
557-565 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
Zinc is routinely employed in the synthesis of InP quantum dots (QDs) to improve the photoluminescence efficiency and carrier mobility of the resulting In(Zn)P alloy nanostructures. The exact location of Zn in the final structures and the mechanism by which it enhances the optoelectronic properties of the QDs is debated. We use synchrotron X-ray absorbance spectroscopy to show that the majority of Zn in In(Zn)P QDs is located at their surface as Zn-carboxylates. However, a small amount of Zn is present inside the bulk of the QDs with the consequent contraction of their lattice, as confirmed by combining high resolution high-angle annular dark-field imaging scanning transmission electron microscopy (HAADF-STEM) with statistical parameter estimation theory. We further demonstrate that the Zn content and its incorporation into the QDs can be tuned by the ligation of commonly employed Zn carboxylate precursors: the use of highly reactive Zn-acetate leads to the formation of undesired Zn3P2 and the final nanostructures being characterized by broad optical features, whereas Zn-carboxylates with longer carbon chains lead to InP crystals with much lower zinc content and narrow optical features. These results can explain the differences between structural and optical properties of In(Zn)P samples reported across the literature, and provide a rational method to tune the amount of Zn in InP nanocrystals and to drive the incorporation of Zn either as surface Zn-carboxylate, as a substitutional dopant inside the InP crystal lattice, or even predominantly as Zn3P2. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000507721600056 |
Publication Date |
2019-12-13 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0897-4756 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
9.466 |
Times cited |
39 |
Open Access |
OpenAccess |
|
| |
Notes |
A.J.H. acknowledges support from the European Research Council Horizon 2020 ERC Grant Agreement No. 678004 (Doping on Demand). This research is supported by the Dutch Technology Foundation TTW, which is part of The Netherlands Organization for Scientific Research (NWO), and which is partly funded by Ministry of Economic Affairs. SB acknowledges funding from the European Research Council (grant 815128 REALNANO). The authors gratefully acknowledge funding from the Research Foundation Flanders (FWO, Belgium) through project funding G.0381.16N and a postdoctoral grant to A.D.B. AJH, LM and JM acknowledge support from the H2020 Collaborative Project TEQ (Grant No. 766900).; sygma |
Approved |
Most recent IF: 9.466 |
|
| |
Call Number |
EMAT @ emat @c:irua:165234 |
Serial |
5438 |
|
| Permanent link to this record |
