锆钛酸铅光学声子的虚晶近似研究

INVESTIGATION OF OPTICAL PHONONS FOR PbZr_xTi_(1-x)O_3 WITH THE VIRTUAL CRYSTAL APPROXIMATION

在虚晶近似框架上用刚性离子模型计算了铁电固溶体PbZrxTi1-xO3 (x =0 2 5～ 0 4 0 )布里渊区Г点的声子振动频率 .结果显示 ,随着Zr组份x的增加 ,光学横模向低频方向移动 。

The phonon vibration frequencies of PbZrxTi1-xO3(x = 0.25similar to0.40) at Gamma point in the Brillioun zone were calculated by using the rigid-ion model in the frame of the virtual crystal approximation. The results show that the transverse optical phonon frequencies of PbZrxTi1-xO3 shift toward the tower frequency with increasing composition x of Zr, which is in accordance with the data of Raman experiments.