摘要
本文测定了不同粒径的钛酸铅纳米晶的ＦＴＲａｍａｎ光谱，确定了各光学声子模的归属，发现Ａ１（１ＴＯ）声子峰的多重劈裂特征，支持了Ｆｏｓｔｅｒ等人的非谐性振动模型。粒径和温度的变化将使声子频率发生位移并带来峰宽的变化，Ａ１（ＴＯ）模比对应的Ｅ（ＴＯ）模频移速度快，当由铁电相到达居里点时，二者将在某一较低频率处汇合。
FT Raman spectra of lead titanate nanocrystals of different grain sizes were measurcd and all optical phonon modes were assigned. The result indicated that the A 1(1TO) phonon appears to be split into multiple peaks which supported the anharmonic vibration model proposed by Foster et al. Changing the grain size and temperature can down shift the phonon frequency lower and broaden width. Furthemore, Below T c the frenquency of the A 1(iTO) mode downshifts faster than corresponding E(iTO) mode.
出处
《光散射学报》
1999年第2期127-131,共5页
The Journal of Light Scattering
基金
黑龙江省自然科学基金
黑龙江大学杰出青年科学基金
关键词
钛酸铅
纳米晶
拉曼光谱
软模
声子
lead titanate
nanocrystal
FT Raman
soft mode
phonon
