期刊
ADVANCED FUNCTIONAL MATERIALS
卷 23, 期 48, 页码 6076-6081出版社
WILEY-V C H VERLAG GMBH
DOI: 10.1002/adfm.201301536
关键词
doped ceria; elastic modulus; nanoindentation; primary creep; point defects
类别
资金
- US-Israel Binational Science Foundation [2008181]
- Minerva Foundation
The influence of dopant size and oxygen vacancy concentration on the room temperature elastic modulus and creep rate of ceria doped with Pr4+, Pr3+, Lu3+, and Gd3+, is investigated using a nanoindentation technique. Measurements are conducted with both fast (15 mN s(-1)) and slow (0.15 mN s(-1)) loading modes, including a load-hold stage at 150 mN of 8 s and 30 s, respectively. Based on the data obtained using the fast loading mode, it is found that: 1) the dopant size is a primary determinant of the elastic modulusthe larger dopants (Pr3+ and Gd3+) produce lower unrelaxed moduli which are independent of the oxygen vacancy concentration. 2) The rearrangement of point defects is the major source of room temperature creep observed during load-hold. Pr3+- and Gd3+-doped ceria display the higher creep rates: due to their large size, they repel oxygen vacancies (V-O), thereby promoting the formation of O-7-Ce-Ce-V-O complexes that are capable of low temperature rearrangement. Lower creep rates are observed for Pr4+- and Lu3+-doped ceria: the former has no vacancies and the latter, immobile vacancies. 3) Nanoindentation is a practical technique for identifying materials with labile point defects, which may indicate useful functionality such as high ionic conductivity, large electrostriction, and inelasticity.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据