MgO和Cu的弹性常数随温度及压强变化关系的研究

Temperature and pressure dependence of elastic moduli of MgO and Cu

从Anderson-Grüneisen参数定义式和热膨胀系数定义式出发,根据Tallon的普遍化理论,推导出了一个用于计算弹性常数的理论模型,用所得到的理论模型分别计算了MgO和Cu两种固体材料的弹性常数C_(11)、C_(12)和C_(44)随压强以及温度变化的理论数值,并将理论计算结果与Kumar模型计算结果以及相关实验数据进行了比较,对所得到的理论模型计算结果与Kumar模型计算结果之间的差异性进行了分析和探讨.研究结果表明:所推导的理论模型计算结果与实验数据更加符合,并且由于所用的推导方法不依赖于晶体的结构,因此该模型具有更好的合理性和普适性.

Based on the definitions of Anderson-Gruneisen parameters and thermal expansion coefficient, the theoretical model for the calculation of elastic constants is deduced from the generalized theory of Tallon. The values of elastic moduli , and of MgO and Cu have been calculated at different temperatures and pressures using the obtained theoretical model. The calculated values are compared with those of Kumar model and the existing experimental data. The differences of calculated values between the present and Kumar models are also analyzed and discussed. The results obtained from the present model are in good agreement with the experimental data. The present method does not depend on the crystal structure, therefore this theoretical model has better rationality and universality.