高压下Gd3Ga5O12晶体的弹性性能

 利用超声“脉冲回波重合法”技术,测定了立方晶体镱镓石榴石（GGG）各对称方向的超声波声速,及它们在流体静压力和单轴应力条件下,随压力的变化,计算了GGG的二阶和三阶弹性常数。它们分别是：c₁₁=3.04,c₁₂=1.31,c₄₄=0.94和c₁₁₁=-17.97,c₁₁₂=-12.86,c₁₂₃=-1.06,c₁₄₄=-2.11,c₁₆₆=-3.29,c₄₅₆=-0.94,单位是10¹¹ N/m²。根据这些数据,我们还计算了GGG晶体的德拜温度以及沿它的001]→111]→110]→100]传播的三个声学波分支（一个纵波,两个横波）的Gruneisen参数γ(p,N)的分布。

ELASTIC BEHAVIOUR OF THE GADOLINIUM GALLIUM GARNET CRYSTAL UNDER HIGH PRESSURE

By means of the "pulse echo overlap method", we have measured the velocities of ultrasonic wave propagating along different crystalline axes of the Gadolinium Gallium Garnet crystal (GGG). We have also measured the changes of the velocities with hydrostatic pressures and uniaxial stresses respectively. The second and third order elastic constants of GGG are obtained as follows: c₁₁=3.04, c₁₂=1.31, c₄₄=0.94, c₁₁₁=-17.97, c₁₁₂=-12.86, c₁₂₃=-1.06, c₁₄₄=-2.11, c₁₆₆=-3.29 and c₄₅₆=-0.94, where the unit is 10¹¹ N/m². From these date we have calculated the Debye temperature and Gruneisen parameters γ(p,N) of GGG crystal from 011] to 111], 110] and 100].