Near-Edge X-ray Absorption Fine Structure Study of Disordering in Gd2(Ti1-yZry)2O7 Pyrochlores

Authors

Ponnusamy Nachimuthu, University of Nevada, Las VegasFollow
S. Thevuthasan, Pacific Northwest National LaboratoryFollow
E. M. Adams, Pacific Northwest National LaboratoryFollow
W. J. Weber, Pacific Northwest National Laboratory
B. D. Begg, Australian Nuclear Science and Technology Organization
B. S. Mun, Lawrence Berkeley National Laboratory
D. K. Shuh, Lawrence Berkeley National LaboratoryFollow
Dennis W. Lindle, University of Nevada, Las VegasFollow
Eric M. Gullikson, Lawrence Berkeley National LaboratoryFollow
Rupert C. Perera, Lawrence Berkeley National LaboratoryFollow

Document Type

Article

Publication Date

2-2005

Publication Title

Journal of Physical Chemistry B

Volume

109

Issue

4

First page number:

1337

Last page number:

1339

Abstract

Disorder in Gd₂(Ti_1-yZr_y)₂O₇ pyrochlores, for y = 0.0-1.0, is investigated by Ti 2p and O 1s near-edge X-ray absorption fine structure spectroscopy. Ti⁴⁺ ions are found to occupy octahedral sites in Gd₂Ti₂O₇ with a tetragonal distortion induced by vacant oxygen sites. As Zr substitutes for Ti, the tetragonal distortion decreases, and Zr coordination increases from 6 to 8. The migration of oxygen ions from 48f or 8b sites to vacant 8a sites compensate for the increased Zr coordination, thereby reducing the number of vacant 8a sites, which further reduces the tetragonal distortion and introduces more disorder around Ti. This is evidence for simultaneous cation disorder with anion migration.

Keywords

Atomic orbitals; Gadolinium; Molecular structure; Titanium; X-ray Absorption Near Edge Structure; Zirconium

Disciplines

Analytical Chemistry | Atomic, Molecular and Optical Physics | Biological and Chemical Physics | Elementary Particles and Fields and String Theory | Physical Chemistry

Language

English

Permissions

Use Find in Your Library, contact the author, or use interlibrary loan to garner a copy of the article. Publisher copyright policy allows author to archive post-print (author’s final manuscript). When post-print is available or publisher policy changes, the article will be deposited

Repository Citation

Nachimuthu, P., Thevuthasan, S., Adams, E. M., Weber, W. J., Begg, B. D., Mun, B. S., Shuh, D. K., Lindle, D. W., Gullikson, E. M., Perera, R. C. (2005). Near-Edge X-ray Absorption Fine Structure Study of Disordering in Gd2(Ti1-yZry)2O7 Pyrochlores. Journal of Physical Chemistry B, 109(4), 1337-1339.