Thermal expansion at elevated temperatures. II. Aluminium oxide: experimental data between 100 and 800 K and their analysis

摘要: Using applications of interferometric apparatus described previously, earlier uncertainties in the linear coefficients thermal expansion high purity single crystal alpha -Al2O3 have been resolved a and c crystallographic axis directions between approximately 100 800 K. The results used association with related measurements specific heat, elastic constants their pressure dependence to calculate mean Gruneisen parameter as function temperature, temperature dependences weighted average vibrational frequencies geometric frequency spectrum. Values moments nu n distribution f( ) calculated for -3