Unravelling local environments in mixed TiO2–SiO2 thin films by XPS and ab initio calculations

Pavel Ondračka, David Nečas, Michèle Carette, Stephane Elisabeth, David Holec, Agnès Granier, Antoine Goullet, Lenka Zajíčková, Mireille Richard-Plouet

Publikation: Beitrag in FachzeitschriftArtikelForschungBegutachtung

10 Zitate (Scopus)

Abstract

Mixed Ti xSi 1 xO 2 oxide can exhibit a partial phase separation of the TiO 2 and SiO 2 phases at the atomic level. The quantification of TiO 2–SiO 2 mixing in the amorphous material is complicated and was so far done mostly by infrared spectroscopy. We developed a new approach to the fitting of X-ray photoelectron spectroscopy data for the quantification of partial phase separation in amorphous Ti xSi 1 xO 2 thin films deposited by plasma enhanced chemical vapour deposition. Several fitting constraints reducing the total number of degrees of freedom in the fits and thus the fit uncertainty were obtained by using core electron binding energies predicted by density functional theory calculations on Ti xSi 1 xO 2 amorphous supercells. Consequently, a decomposition of the O 1s peak into TiO 2, SiO 2 and mixed components was possible. The component areas ratios were compared with the ratios predicted by older theoretical models based on the atomic environment statistics and we also developed several new models corresponding to more realistic atomic structure and partial mixing. Based on the comparison we conclude that the studied films are mostly disordered, with only a moderate phase separation.

OriginalspracheEnglisch
Aufsatznummer145056
Seitenumfang11
FachzeitschriftApplied surface science
Jahrgang510.2020
Ausgabenummer30 April
Frühes Online-Datum8 Jan. 2020
DOIs
PublikationsstatusVeröffentlicht - 30 Apr. 2020

Bibliographische Notiz

Funding Information:
This work was supported by Ministry of Education, Youth and Sports of the Czech Republic under the project CEITEC 2020 (LQ1601), by the MOBILITY projects 7AMB15AT017 and 7AMB15FR036 , and from the Large Infrastructures for Research, Experimental Development and Innovations project IT4Innovations National Supercomputing Center – LM2015070. The computational results presented have been also in part achieved using the Vienna Scientific Cluster (VSC). This work has been supported by Campus France , the French agency for the promotion of higher education and international mobility.

Publisher Copyright:
© 2020 Elsevier B.V.

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