AlN晶体声子谱及其热学性能的第一原理计算  

First-principle calculation of phonon spectra and thermal properties of AlN crystal

作　　者：郭连权[1] 张智勇[1] 刘嘉慧[2] 冷利[1] 李大业[2] 林琳[1] 

机构地区：[1]沈阳工业大学理学院,沈阳110870 [2]沈阳工业大学基础教育学院,沈阳110870

出　　处：《沈阳工业大学学报》2013年第6期630-634,共5页Journal of Shenyang University of Technology

基　　金：辽宁省教育厅重点实验室基金资助项目(20080024)

摘　　要：针对AlN晶体的声子谱和热学性能,采用密度泛函理论、第一性原理以及ABINIT软件进行了理论计算,得到了AlN晶体的声子谱以及内能、质量定容热容、熵和自由能与温度的关系曲线,并对曲线进行了理论分析.计算结果表明:AlN晶体的声子谱有12条曲线,其中3支为声学波,9支为光学波,并且形成了一光学带隙.AlN晶体的内能随着温度的增加而增加;质量定容热容起初随着温度的增加而较快地增加,后来逐渐达到稳定值;熵随着温度的增加也在增加,并且关系曲线有一定的弯曲;自由能随着温度的增加在不断地减小.以上计算结果与物理规律具有一致性.Aiming at the phonon spectra and thermal properties of A1N crystal, the theoretical calculation was performed with the density functional theory, first-principles and ABINIT software. The phonon spectra of AIN crystal as well as the curves for the internal energy, heat capacity, entropy and free energy as a function of temperature were obtanined, and the curves were theoretically analyzed. The calculated results show that the A1N crystal has 12 phonon spectra curves, where 3 branches are for acoustic wave and 9 branches are for optical wave, and a optical band gap forms. With increasig the temperature, the internal energy of A1N crystal increases, while the heat capacity increases rapidly at first and then gradually achieves the stable value. With increasig the temperature, the entropy also increases, and the relationship curve exhibits certain bending, while the free energy continuously decreases. The above-mentioned calculated results are in accord with the physical rules.

关 键 词：氮化铝 密度泛函理论 第一性原理 ABINIT软件 声子 内能 热容量 熵 自由能 

分 类 号：TB303[一般工业技术—材料科学与工程]