摘要
本文采用超声脉冲回波法在4.2K—300K温区内测试了锗酸铋晶体[110]和[111]晶向的超声纵波衰减与温度的关系,结果在50K附近均出现由于激活弛豫过程所引起的大的异常衰减峰;本文还用脉冲回波重合法精密测定了[100],[110]和[111]晶向的超声纵波和横波的声速,并由此计算出弹性常数C_(11),C_(44)和C_(12)。
Temperature dependences of ultrasonic longitudinal wave attenuation have been measured for bismuth germanium oxide in th [110] and [111] directions from 4.2 K to 300 K using ultrasonic pulse echo technique. There is a large anomalous absorption peak in the vicinity of 50 K in the [110] and [111] directions. This behavior indicates an activated relaxation process of Bi12GeO20 crystal itself.The sound velocities of longitudinal and shear waves in Bi12GeO20 crystal have accurately been measured in the [100] , [110] and [111] directions with pulse-echo-overlap (PEO) technique anh the elastic constants C11,C44 and C12 have been determined.
出处
《声学学报》
EI
CSCD
北大核心
1989年第3期220-225,共6页
Acta Acustica
