中文摘要：

结合连续弹性理论和第一性原理方法,对氮化铝晶体的热膨胀系数和高温弹性系数进行了理论计算。计算结果表明,当温度高于500 K时,六角和立方氮化铝的热膨胀系数随温度升高呈线性增加。当温度为2000K时,六角氮化铝轴、轴的热膨胀系数分别为0.853 49×105K1和0.849 64×105K1;立方氮化铝轴的热膨胀系数为1.353 7×105K1。当温度从0 K升高到2 000 K,六角氮化铝的弹性系数11,12,13,33和44下降幅度分别为10.61%,4.52%,2.0%,13.80%和20.76%,而立方氮化铝的弹性系数11,12和44的下降幅度分别为29.23%,35.33%和21.10%。

英文摘要：

By combining continual elastic theory and first principle calculation,the thermal expansion coefficients and elastic constants of AlN have been studied in this work.It was indicated that the thermal expansion coefficient for both hexagonal and cubic AlN increases linearly with temperature above 500 K.At 2 000 K,the thermal expansion coefficient for hexagonal AlN is 0.853？K and 0.850？K along lattice and,respectively,while for cubic AlN,the thermal expansion coefficient is 1.353？K.Within the temperature range from 0 to 2 000 K,for hexagonal AlN,the elastic constants,,,and decrease by 10.61%,4.52%,2.0%,13.80% and 20.76%,respectively,while for cubic AlN,the elastic constants,and decrease by 29.23%,35.33% and 21.10%,respectively.