CeK-edge EXAFS study of nanocrystalline CeO2

被引：34

作者：

Lee, JF

Tang, MT

Shih, WC

Liu, RS ^{[1
]}

机构：

[1] Natl Taiwan Univ, Dept Chem, Taipei 10764, Taiwan

[2] Synchrotron Radiat Res Ctr, Hsinchu, Taiwan

来源：

MATERIALS RESEARCH BULLETIN | 2002年 / 37卷 / 03期

关键词：

inorganic compounds; nanostructures; oxides; XAFS;

D O I：

10.1016/S0025-5408(02)00671-2

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Nanocrystalline CeO2 samples were prepared via precipitation from aqueous cerium(IV) sulfate solution under a controlled pH. After being subjected to calcination at various temperatures to yield different particle sizes, the local structure around Ce atom was investigated by using EXAFS spectroscopy at Ce K-edge. The first shell Ce-O distance was found to be slightly shorter with small CeO2 particles, indicating a contraction of the lattice. There exists a significant growth in coordination number of the second cell Ce-Ce when the particle size became larger. In terms of Debye-Waller factor (sigma(2)), the first three coordination shells showed a consistent trend, i.e. the degree of disorder increases with reduced particle size. Moreover, sigma(2) of the second shell was found to be smaller than that of the first shell for all samples. (C) 2002 Elsevier Science Ltd. All rights reserved.

引用

页码：555 / 562

页数：8

共 17 条

[1]

Agarwal B. K., 1979, XRAY SPECTROSCOPY

[2]

ASAKURA K, 1986, J PHYS C SOLID STATE, V8, P185

[3] BINDING-ENERGY AND ELECTRONIC-STRUCTURE OF SMALL COPPER PARTICLES [J].