Effect of annealing atmosphere on the structure and dielectric properties of unfilled tungsten bronze ceramics Ba4PrFe0.5Nb9.5O30

被引：14

作者：

Guo, Zhe ^{[1
]}

Zhu, Qihua ^{[1
]}

Wu, Shan ^{[1
]}

Hu, Changzheng ^{[1
]}

Liu, Laijun ^{[1
]}

Fang, Liang ^{[1
]}

机构：

[1] Guilin Univ Technol, Coll Mat Sci & Engn, Guangxi Univ Key Lab Nonferrous Met Oxide Elect F, Key Lab New Proc Technol Nonferrous Met & Mat,Min, Guilin 541004, Peoples R China

来源：

CERAMICS INTERNATIONAL | 2018年 / 44卷 / 07期

基金：

中国国家自然科学基金;

关键词：

Tungsten bronze; Annealing; Structure; Dielectric properties; Electrical properties; Mixed valence;

D O I：

10.1016/j.ceramint.2018.01.196

中图分类号：

TQ174 [陶瓷工业]; TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

Unfilled tungsten bronze ceramics with the nominal formula Ba4PrFe0.5Nb9.5O30 were synthesized via the standard solid-state sintering route, and the effects of oxygen vacancies on the dielectric and electrical properties were investigated in addition to the structure. Room-temperature X-ray diffraction showed that the N-2-annealed sample had the largest cell volume. Low-temperature spectrum showed that N-2 annealing rendered the dielectric constant and dielectric loss more frequency dispersive, whereas O-2 annealing inhibited the frequency dispersion. The dc conductivity of all the samples originated from the electrons produced in the second ionization of oxygen vacancies and was most likely controlled by a mixed conduction mechanism of the electron and oxygen-vacancy ions. The N-2-annealed sample has the highest dc conductivity owing to its high concentration of oxygen vacancies. The broadening of the Raman lines and the decrease of Raman intensity for the N-2-annealed sample originated from a significant structural disorder. X-ray photoelectron spectra demonstrated that the increased oxygen vacancies caused by the change of valences of Fe and Pr ions contributed to the structural disorder.

引用

页码：7700 / 7708

页数：9

共 30 条

[1] Raman characterization of Pb2Na1-xLaxNb5-xFexO15 and Pb0.5(5-x)LaxNb5-xFexO15 (0≤x≤1) solid solutions [J].