Study of High-Temperature Stability of Pyrochlore Zirconates  

作　　者：范群波 王富耻 张慧玲 

机构地区：[1]School of Materials Science and Engineering,Beijing Institute of Technology

出　　处：《Journal of Beijing Institute of Technology》2010年第1期99-102,共4页北京理工大学学报（英文版）

基　　金：Sponsored by the National Natural Science Foundation of China (50801005)

摘　　要：Based on defect chemistry theory and molecular dynamics,the defect formation energy and its relationship with the mechanism of pyrochlore-fluorite phase change were investigated,so as to reveal the underlying mechanism of high-temperature stability of pyrochlore zirconates.Results showed that with the rise of the atom mass of A,the defect formation energies decreased that meant the crystal structure tended to become more disordered.Noticeably,the first nearest cation antisite dominated the pyrochlore disorder transformation process.In addition,it was found that the diffusion of oxygen atoms was far higher than that of cations,and was increased with the temperature,thus also promoting the pyrochlore-fluorite transformation process.Based on defect chemistry theory and molecular dynamics,the defect formation energy and its relationship with the mechanism of pyrochlore-fluorite phase change were investigated,so as to reveal the underlying mechanism of high-temperature stability of pyrochlore zirconates.Results showed that with the rise of the atom mass of A,the defect formation energies decreased that meant the crystal structure tended to become more disordered.Noticeably,the first nearest cation antisite dominated the pyrochlore disorder transformation process.In addition,it was found that the diffusion of oxygen atoms was far higher than that of cations,and was increased with the temperature,thus also promoting the pyrochlore-fluorite transformation process.

关 键 词：high-temperature stability pyrochlore zirconates defect formation energy 

分 类 号：O611.3[理学—无机化学]