摘要
The 1/2{111}-type ordered structure observed in lanthanum-modified lead zirconate titanate has been proved to be stable in the next-nearest-neighbor approximation by the eightpoint cluster variation method.The order parameter as a function of the composition of La3+and lead vacancies and the order-disorder phase diagram have been obtained.
基金
Supported by the National Natural Science Foundation of China under Grant No.59572036。
