Probing Cation Antisite Disorder in Gd2Ti2O7 Pyrochlore by Site-specific NEXAFS and XPS

Authors

Ponnusamy Nachimuthu, University of Nevada, Las VegasFollow
S. Thevuthasan, Pacific Northwest National LaboratoryFollow
Mark H. Engelhard, Pacific Northwest National LaboratoryFollow
W. J. Weber, Pacific Northwest National Laboratory
D. K. Shuh, Lawrence Berkeley National LaboratoryFollow
N. M. Hamdan, Lawrence Berkeley National Laboratory
B. S. Mun, Lawrence Berkeley National Laboratory
E. M. Adams, Pacific Northwest National LaboratoryFollow
D. E. McCready, Pacific Northwest National Laboratory
V. Shutthanandan, Pacific Northwest National LaboratoryFollow
Dennis W. Lindle, University of Nevada, Las VegasFollow
G. Balakrishnan, University of WarwickFollow
R. C. Ewing, University of Michigan - Ann Arbor

Document Type

Article

Publication Date

9-2004

Publication Title

Physical Review B

Volume

70

Issue

10

First page number:

4

Abstract

Disorder in Gd₂Ti₂O₇ is investigated by near-edge x-ray-absorption fine structure (NEXAFS) and x-ray photoelectron spectroscopy (XPS). NEXAFS shows Ti⁴⁺ ions occupy octahedral sites with a tetragonal distortion induced by vacant oxygen sites. O 1s XPS spectra obtained with a charge neutralization system from Gd₂Ti₂O₇(100) and the Gd₂Ti₂O₇ pyrochlore used by Chen et al. [Phys. Rev. Lett. 88, 105901 (2002)], both yielded a single peak, unlike the previous result on the latter that found two peaks. The current results give no evidence for an anisotropic distribution of Ti and O. The extra features reported in the aforementioned communication resulted from charging effects and incomplete surface cleaning. Thus, a result confirming the direct observation of simultaneous cation-anion antisite disordering and lending credence to the split vacancy model has been clarified.

Keywords

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

Disciplines

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

Language

English

Permissions

Copyright American Physical Society, used with permission

Repository Citation

Nachimuthu, P., Thevuthasan, S., Engelhard, M. H., Weber, W. J., Shuh, D. K., Hamdan, N. M., Mun, B. S., Adams, E. M., McCready, D. E., Shutthanandan, V., Lindle, D. W., Balakrishnan, G., Ewing, R. C. (2004). Probing Cation Antisite Disorder in Gd2Ti2O7 Pyrochlore by Site-specific NEXAFS and XPS. Physical Review B, 70(10), 4.
https://digitalscholarship.unlv.edu/chem_fac_articles/51