钙钛矿氟化物ABF_3晶体中Gd^(3+)-V_B和Gd^(3+)-M^+中心的四角畸变研究

摘要

The tetragonal distortions of Gd 3+-VB and Gd 3+-M + centers in fluoroperovskites ABF3 （A=K,Rb,Cs;B= Cd,Ca） are studied by calculating the EPR zero-field splitting b 02. From the studies,an interesting trend is found,i.e., when the size of M + ion is close to that of the replaced host ion,the tetragonal distortion ΔR in Gd 3+-M + centers is smaller than that in Gd 3+-VB center,whereas when the size of M + ion is much smaller than that of the replaced host ion,the distortion ΔR becomes larger. The causes of the trend are discussed.