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Title: Temperature Dependence of XANES Spectra for ATiO3, A2TiO4 and TiO2 Compounds with Structural Phase Transitions

Abstract

Ti K-edge X-ray absorption near edge structure (XANES) spectra of various titanates was measured at various temperatures. The composition, structure and temperature dependence of XANES spectra was investigated especially on the phase transition. Ti atoms are located in TiO6 octahedral sites for the all samples. Ti K-edge XANES spectra change largely with different compositions, while the temperature dependence of XANES spectra is small in each compound even if undergoing structural phase transition. For the temperature dependence, the pre-edge intensity has two types of behavior. One is decreasing as temperatures increase, the other is increasing. The former is for PbTiO3 and BaTiO3 perovskite and the later is for CaTiO3 and SrTiO3 perovskite, Mg2TiO4 spinel and TiO2 rutile.

Authors:
;  [1];  [2];  [3];  [4]
  1. Faculty of Science, Kumamoto University, Kumamoto 860-8555, (Japan)
  2. Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama 226-850 (Japan)
  3. Max-Planck-Institute FKF. Heisenbergstr. 1, 70569 Stuttgart (Germany)
  4. Department of Advanced Material Science and Engineering, Yamaguchi University, Yamaguchi 775-861 (Japan)
Publication Date:
OSTI Identifier:
21054645
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 882; Journal Issue: 1; Conference: XAFS13: 13. international conference on X-ray absorption fine structure, Stanford, CA (United States), 9-14 Jul 2006; Other Information: DOI: 10.1063/1.2644548; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ABSORPTION SPECTRA; ABSORPTION SPECTROSCOPY; BARIUM COMPOUNDS; CALCIUM COMPOUNDS; LEAD COMPOUNDS; MAGNESIUM COMPOUNDS; PEROVSKITE; PHASE TRANSFORMATIONS; RUTILE; SOLIDS; SPINELS; STRONTIUM TITANATES; TEMPERATURE DEPENDENCE; TITANIUM OXIDES; TRANSITION TEMPERATURE; X-RAY SPECTRA; X-RAY SPECTROSCOPY

Citation Formats

Hashimoto, Takafumi, Yoshiasa, Akira, Okube, Maki, Okudera, Hiroki, and Nakatsuka, Akihiko. Temperature Dependence of XANES Spectra for ATiO3, A2TiO4 and TiO2 Compounds with Structural Phase Transitions. United States: N. p., 2007. Web. doi:10.1063/1.2644548.
Hashimoto, Takafumi, Yoshiasa, Akira, Okube, Maki, Okudera, Hiroki, & Nakatsuka, Akihiko. Temperature Dependence of XANES Spectra for ATiO3, A2TiO4 and TiO2 Compounds with Structural Phase Transitions. United States. doi:10.1063/1.2644548.
Hashimoto, Takafumi, Yoshiasa, Akira, Okube, Maki, Okudera, Hiroki, and Nakatsuka, Akihiko. Fri . "Temperature Dependence of XANES Spectra for ATiO3, A2TiO4 and TiO2 Compounds with Structural Phase Transitions". United States. doi:10.1063/1.2644548.
@article{osti_21054645,
title = {Temperature Dependence of XANES Spectra for ATiO3, A2TiO4 and TiO2 Compounds with Structural Phase Transitions},
author = {Hashimoto, Takafumi and Yoshiasa, Akira and Okube, Maki and Okudera, Hiroki and Nakatsuka, Akihiko},
abstractNote = {Ti K-edge X-ray absorption near edge structure (XANES) spectra of various titanates was measured at various temperatures. The composition, structure and temperature dependence of XANES spectra was investigated especially on the phase transition. Ti atoms are located in TiO6 octahedral sites for the all samples. Ti K-edge XANES spectra change largely with different compositions, while the temperature dependence of XANES spectra is small in each compound even if undergoing structural phase transition. For the temperature dependence, the pre-edge intensity has two types of behavior. One is decreasing as temperatures increase, the other is increasing. The former is for PbTiO3 and BaTiO3 perovskite and the later is for CaTiO3 and SrTiO3 perovskite, Mg2TiO4 spinel and TiO2 rutile.},
doi = {10.1063/1.2644548},
journal = {AIP Conference Proceedings},
number = 1,
volume = 882,
place = {United States},
year = {Fri Feb 02 00:00:00 EST 2007},
month = {Fri Feb 02 00:00:00 EST 2007}
}
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  • Correlations between the temperature dependence of paramagnetic susceptibility between 20 and 300 deg K and T/sub c/ for compounds in the system Nb/sub 3/(Al,Ge) are interpreted in terms of changes in the density of electronic states. (AIP)
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  • X-ray absorption spectroscopy (XAS) was utilized to investigate both the Au particle size on several supports composed by silica and titanium oxide, and the coordination of TiO2 in the support phase. Particularly, we wanted to utilize the technique to probe mixing in the support phase, by using different synthetic methods such as by functionalizing silica or by ALD (atomic layer deposition) techniques as prepared in our laboratories, and the growth and stability of Au nanoparticles deposited on these supports. The study using cosynthesis techniques to dope bulk mesoporous SiO2 with TiO2 resulted in TiO2 being dispersed in the SiO2 matrix;more » however, a second phase starts forming as the TiO2 content increases as indicated by the EXAFS Ti-O shell shift in position and increase of coordination number. On the supports prepared by cosynthesis, Au particles were smaller and more stable. The study using the surface sol-gel technique for deposition of single monolayers of an oxide such as TiO2 produced Ti environments in which the Ti-O shell and the next two Ti-Ti shells lie on the same position as expected for an anatase structure. Although undercoordinated, the presence of the Ti-Ti shells indicate that the titania species are not molecularly dispersed on the SiO2 surface as hypothesized, but there is indeed a cross-linking of the titania moieties.« less