稀土元素La掺杂对AlN性能影响的第一性原理研究

本文通过基于密度泛函理论的第一性原理计算方法研究了稀土元素La掺杂对纤锌矿结构AlN力学性能及压电性能的影响.计算得到的AlN各项力学性能及压电性能与实验值较吻合.掺杂稀土元素La会降低其体模量、剪切模量与杨氏模量,但会使AlN由脆性材料转变为韧性材料.压电性能计算结果表明,掺杂稀土元素La后,可使体系的压电性能提升15%左右.电子结构分析结果表明La的引入会降低体系中化学键的作用强度,从而提升了体系的塑性及压电性能.

First principles Study on the Effect of Rare Earth Element La Doping on the Properties of AlN

In this paper, the effect of rare earth element La doping on the mechanical properties and piezoelectric properties of wurtzite structure AlN were studied by using the first principles calculations based on the density functional theory. The calculated mechanical and piezoelectric properties of AlN are in good agreement with the experimental results. Doping rare earth element La will reduce its bulk modulus, shear modulus and Young''s modulus, but will change AlN from brittle material to ductile material. The calculation results of piezoelectric properties show that the doping of rare earth element La can enhance the piezoelectric properties of the system by about 15%. The results of electronic structure analysis show that the introduction of La can reduce the strength of chemical bonds in the system, thus improving the plastic and piezoelectric properties of the system.