WAXS and PDF-based analyses of chromium doping in nanocrystalline titania (anatase and brookite)

Hengzhong Zhang, Benjamin Gilbert, Bin Chen, Julian F. Banfield

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review

Abstract

Chromium-doped (0.5-10 % Cr:Ti molar ratio) nanocrystalline titania (5-6 nm) prepared via sol-gel method was examined by synchrotron-based wide angle x-ray scattering (WAXS) for crystal structure determination. Atomic pair-distribution functions (PDF) for both raw and heattreated samples were obtained by Fourier transforms of the WAXS data. The PDF data were fitted using structural models of nanocrystalline titania that considered phase compositions, lattice parameters, atomic positions and thermal factors. The unit cell of Cr-doped nanocrystalline titania expanded 1-2 % with respect to bulk titania as a consequence of the substitution of Ti by Cr and the generation of oxygen vacancies. We observed a lattice contraction after heat-treatment that may be caused by the redistribution of Cr atoms to nanoparticle surfaces during phase transformation and particle coarsening.

Original languageEnglish
Title of host publicationNanostructured Materials and Hybrid Composites for Gas Sensors and Biomedical Applications
PublisherMaterials Research Society
Pages237-242
Number of pages6
ISBN (Print)9781558998711
DOIs
Publication statusPublished - 2006
Externally publishedYes
EventMaterials Research Society Symposium (MRS) 2006 (Spring) - San Francisco, United States of America
Duration: 17 Apr 200621 Apr 2006

Publication series

NameMaterials Research Society Symposium Proceedings
Volume915
ISSN (Print)0272-9172

Conference

ConferenceMaterials Research Society Symposium (MRS) 2006 (Spring)
Abbreviated titleMRS 2006 Spring
Country/TerritoryUnited States of America
CitySan Francisco
Period17/04/0621/04/06

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