Determination of Ce4+/Ce3+ in electron-beam-damaged CeO2 by electron energy-loss spectroscopy

被引：220

作者：

Garvie, LAJ ^{[1
]}

Buseck, PR

机构：

[1] Arizona State Univ, Dept Geol, Tempe, AZ 85287 USA

[2] Arizona State Univ, Dept Chem Biochem, Tempe, AZ 85287 USA

来源：

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS | 1999年 / 60卷 / 12期

基金：

美国国家科学基金会;

关键词：

oxides; electron energy loss spectroscopy (EELS); radiation damage;

D O I：

10.1016/S0022-3697(99)00218-8

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

We followed the reduction of Ce4+ in CeO2 by observing changes in the shape of the Ce M-4,M-5 edge by parallel electron energy-loss spectroscopy with a transmission electron microscope. The energy-loss near-edge structure of the beam-damaged CeO2 exhibits Ce M-4,M-5, and O K-edge shapes that are consistent with reduction to a Ce3+ oxide. During the damage process the spectrum of CeO2 changes as follows: (a) decreases in energies of the M-5 and M-4 maxima; (b) changes in shape of the near-edge structure; (c) inversion of the M-5 to M-4 branching ratio; and (d) increase in the M-5 to M-4 area ratio. We simulated M-4,M-5 edges of damaged CeO2 with a linear combination of Ce4+ and Ce3+ spectra and observed no intermediate oxidation states. (C) 1999 Elsevier Science Ltd. All rights reserved.

引用

页码：1943 / 1947

页数：5

共 22 条

[1] X-RAY-ABSORPTION NEAR-EDGE STRUCTURE STUDY IN MIXED-VALENT SAMARIUM SYSTEMS [J].