非简谐振动对SiC的热膨胀系数数和介电性能的影响

利用抛物型电子能谱模型，考虑到原子的非简谐振动，求出了SiC中原子振动的简谐系数与非简谐系数，用固体物理理论和方法，得到了SiC的热膨胀系数和格林乃森参量以及介电常数随温度变化的解析式，探讨了原子非简谐振动对的影响。结果表明：的格林乃森参量和热膨胀系数均随温度升高而非线性增大，而介电常数随温度升高而非线性减小；原子振动的非简谐项（特别是第二非简谐项）对的热膨胀等热学性质和介电性能有重要影响，温度愈高，非简谐振动项的影响愈大。

Effect of non - harmonic vibration on SiC thermal expansion coefficient and dielectric properties

Harmonic coefficient and anharmonic coefficient of SiC atomic vibration is investigated by using parabola electron spectroscopy model in case of anharmonic vibration of atoms. By using theory and methods of solid-state physics, we get the thermal expansion coefficient and Grüneisen parameter of SiC and analytical expressions of dielectric constant with temperature, then the influence of atomic anharmonic vibration is also discussed. The results show that the Grüneisen parameter and thermal expansion coefficient of SiC nonlinear increases as temperature increased, while the dielectric constant decreases nonlinearly with increasing the temperature. The anharmonic terms (especially the second anharmonic terms) of the atomic vibration have an important influence on the thermal and dielectric properties of the thermal expansion. The higher the temperature, the more influence of anharmonic vibration terms.