1. An X-Ray Diffraction and Thermogravimetric Study of Layered Perovskite Y1-xBixBaCo4O7.
- Author
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Zhang Ya-Mei, Han Ru-Qu, Wu Xiao-Shan, and Wang Zhi-He
- Subjects
PEROVSKITE ,YTTRIUM ,X-ray diffraction ,THERMOGRAVIMETRY ,LAYER structure (Solids) ,BISMUTH - Abstract
Layer-structured oxides Y
1-x Bix BaCo4 O7 (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 Y0.95 Bi0.05 BaCo4 O7 , it is found that the structure and oxygen absorption properties of Y1-x Bix BaCo4 O7 are affected significantly as the Bi content x increases. Rietveld refinement results show that Y1-x Bix BaCo4 O7 (x ≤ 0.05) is single phase with a hexagonal crystal structure (space group P63 mc). Unit cell parameters and volume are changed and CoO4 tetrahedra are distorted along the c-axis in Bi doped YBaCo4 O7 . The TG results show that Y1-x Bix BaCo4 O7 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 YBaCo4 O7 . 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. [ABSTRACT FROM AUTHOR]- Published
- 2011
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