摘要
Layer-structured oxides Y_(1−x)Bi_(x)BaCo_(4)O_(7)(0.00≤x≤0.05)were successfully synthesized and their structural and oxygen absorption properties were investigated by x−ray diffraction and thermogravimetry.Though Bi solubility was limited to about 5%,corresponding to Y0.95Bi0.05BaCo4O7,it is found that the structure and oxygen absorption properties of Y_(1−x)Bi_(x)BaCo_(4)O_(7) are affected significantly as the Bi content x increases.Rietveld refinement results show that Y_(1−x)Bi_(x)BaCo_(4)O_(7)(x≤0.05)is single phase with a hexagonal crystal structure(space group P63mc).Unit cell parameters and volume are changed and CoO4 tetrahedra are distorted along the c−axis in Bi doped YBaCo_(4)O_(7).The TG results show that Y_(1−x)Bi_(x)BaCo_(4)O_(7) undergoes two oxygen absorption processes in oxygen from room temperature to 1000°C and the maximum mass increase of the doped samples is less than that of YBaCo4O7.Bi doping effects on the structure and oxygen absorption properties are discussed on the basis of average radius and disorder of the Y site,the valence of Bi and the oxygen activation energy.
作者
ZHANG Ya-Mei
HAN Ru-Qu
WU Xiao-Shan
WANG Zhi-He
张亚梅;韩汝取;吴小山;王智河(Jiangsu University of Science and Technology,Zhenjiang 212003;Laboratory of Solid State Microstructures,Department of Physics,Nanjing University,Nanjing 210093)
基金
Supported by the Doctorial Start-up Fund of Jiangsu University of Science and Technology,and the Natural Science Foundation of Jiangsu University of Science and Technology(No 2009SL153J).
