|
Records |
Links |
|
Author |
Volykhov, A.A.; Frolov, A.S.; Neudachina, V.S.; Vladimirova, N.V.; Gerber, E.; Callaert, C.; Hadermann, J.; Khmelevsky, N.O.; Knop-Gericke, A.; Sanchez-Barriga, J.; Yashina, L.V. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
|
|
Title |
Impact of ordering on the reactivity of mixed crystals of topological insulators with anion substitution: Bi₂SeTe₂ and Sb₂SeTe₂ |
Type |
A1 Journal article |
|
Year |
2021 |
Publication |
Applied Surface Science |
Abbreviated Journal |
Appl Surf Sci |
|
|
Volume |
541 |
Issue |
|
Pages |
148490 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
Three-dimensional topological insulators are exotic materials with unique properties. Tetradymite type binary chalcogenides of bismuth and antimony, as well as their mixed crystals, belong to prototypical TIs. Potential device applications of these materials require in-depth knowledge of their stability in the ambient atmosphere and other media maintained during their processing. Here we investigated the reactivity of mixed crystals with anion substitution, Bi-2(Se1-xTex)(3) and Sb2(Se1-xTex)(3), towards molecular oxygen using both in situ and ex situ X-ray photoelectron spectroscopy. The results indicate that, in contrast to cation substitution, partial substitution of tellurium by selenium atoms leads to anomalously high surface reactivity, which even exceeds that of the most reactive binary constituent. We attribute this effect to anion ordering that essentially modifies the bond geometry, especially the respective bond angles as modeled by DFT. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000608492900003 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2020-11-18 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0169-4332 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.387 |
Times cited |
|
Open Access |
Not_Open_Access |
|
|
Notes |
|
Approved |
Most recent IF: 3.387 |
|
|
Call Number |
UA @ admin @ c:irua:176067 |
Serial |
6728 |
|
Permanent link to this record |
|
|
|
|
Author |
Sirotina, A.P.; Callaert, C.; Volykhov, A.A.; Frolov, A.S.; Sanchez-Barriga, J.; Knop-Gericke, A.; Hadermann, J.; Yashina, L.V. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
|
|
Title |
Mechanistic studies of gas reactions with multicomponent solids : what can we learn by combining NAP XPS and atomic resolution STEM/EDX? |
Type |
A1 Journal article |
|
Year |
2019 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
|
|
Volume |
123 |
Issue |
43 |
Pages |
26201-26210 |
|
|
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
Rapid development of experimental techniques has enabled real time studies of solid gas reactions at the level reaching the atomic scale. In the present paper, we focus on a combination of atomic resolution STEM/EDX, which visualizes the reaction zone, and near ambient pressure (NAP) XPS, which collects information for a surface layer of variable thickness under reaction conditions. We compare the behavior of two affined topological insulators, Bi2Te3 and Sb2Te3. We used a simple reaction with molecular oxygen occurring at 298 K, which is of practical importance to avoid material degradation. Despite certain limitations, a combination of in situ XPS and ex situ cross-sectional STEM/EDX allowed us to obtain a self-consistent picture of the solid gas reaction mechanism for oxidation of Sb2Te3 and Bi2Te3 crystals, which includes component redistribution between the oxide and the subsurface layer and Te segregation with formation of a thin ordered layer at the interface. The process is multistep in case of both compounds. At the very beginning of the oxidation process the reactivity is determined by the energy benefit of the corresponding element oxygen bond formation. Further in the oxidation process, the behavior of these two compounds becomes similar and features component redistribution between the oxide and the subsurface layer. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000493865700019 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2019-10-03 |
|
|
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 |
|
|
|
Notes |
|
Approved |
Most recent IF: 4.536 |
|
|
Call Number |
UA @ admin @ c:irua:164664 |
Serial |
6310 |
|
Permanent link to this record |
|
|
|
|
Author |
Volykhov, A.A.; Sanchez-Barriga, J.; Batuk, M.; Callaert, C.; Hadermann, J.; Sirotina, A.P.; Neudachina, V.S.; Belova, A.I.; Vladimirova, N.V.; Tamm, M.E.; Khmelevsky, N.O.; Escudero, C.; Perez-Dieste, V.; Knop-Gericke, A.; Yashina, L.V. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
|
|
Title |
Can surface reactivity of mixed crystals be predicted from their counterparts? A case study of (Bi1-xSbx)2Te3 topological insulators |
Type |
A1 Journal article |
|
Year |
2018 |
Publication |
Journal of materials chemistry C : materials for optical and electronic devices |
Abbreviated Journal |
J Mater Chem C |
|
|
Volume |
6 |
Issue |
33 |
Pages |
8941-8949 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
The behavior of ternary mixed crystals or solid solutions and its correlation with the properties of their binary constituents is of fundamental interest. Due to their unique potential for application in future information technology, mixed crystals of topological insulators with the spin-locked, gapless states on their surfaces attract huge attention of physicists, chemists and material scientists. (Bi1-xSbx)(2)Te-3 solid solutions are among the best candidates for spintronic applications since the bulk carrier concentration can be tuned by varying x to obtain truly bulk-insulating samples, where the topological surface states largely contribute to the transport and the realization of the surface quantum Hall effect. As this ternary compound will be evidently used in the form of thin-film devices its chemical stability is an important practical issue. Based on the atomic resolution HAADF-TEM and EDX data together with the XPS results obtained both ex situ and in situ, we propose an atomistic picture of the mixed crystal reactivity compared to that of its binary constituents. We find that the surface reactivity is determined by the probability of oxygen attack on the Te-Sb bonds, which is directly proportional to the number of Te atoms bonded to at least one Sb atom. The oxidation mechanism includes formation of an amorphous antimony oxide at the very surface due to Sb diffusion from the first two quintuple layers, electron tunneling from the Fermi level of the crystal to oxygen, oxygen ion diffusion to the crystal, and finally, slow Te oxidation to the +4 oxidation state. The oxide layer thickness is limited by the electron transport, and the overall process resembles the Cabrera-Mott mechanism in metals. These observations are critical not only for current understanding of the chemical reactivity of complex crystals, but also to improve the performance of future spintronic devices based on topological materials. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000443279300007 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2018-07-20 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2050-7526; 2050-7534 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
5.256 |
Times cited |
3 |
Open Access |
Not_Open_Access |
|
|
Notes |
; The authors acknowledge financial support within the bilateral program "Russian-German Laboratory at BESSY II''. We thank Helmholtz-Zentrum Berlin for granting access to the beamlines RGBL, UE112-PGM2a and ISISS. Support of ALBA staff during measurements at the CIRCE beamline is gratefully acknowledged. We thank Dr Ivan Bobrikov for support in the XRD measurements and Daria Tsukanova for the participation in crystal preparation and XPS measurements. A. Volykhov thanks RSF (grant 18-73-00248) for financial support. A. I. Belova acknowledges support from the G-RISC Centre of Excellence. The work was supported by Helmholtz Gemeinschaft (Grant No. HRJRG-408) and RFBR (grant 14-03-31518). J. H. and C. C. acknowledge support from the University of Antwerp through the BOF grant 31445. ; |
Approved |
Most recent IF: 5.256 |
|
|
Call Number |
UA @ lucian @ c:irua:153647 |
Serial |
5080 |
|
Permanent link to this record |