铟钇金属间化合物力学性能的第一性原理计算

First-principles calculations for the mechanical properties of In-Y intermetallic compounds

本文基于密度泛函理论的平面波超软赝势方法,对铟钇(In-Y)金属间化合物的力学结构稳定性、弹性性质和热力学性能进行了研究.通过结构优化得到了In3Y、InY、InY2三种金属间化合物的晶格常数,发现与实验值比较吻合.弹性常数的计算结果表明In-Y金属间化合物的结构是稳定的,由弹性常数推算出In3Y、InY、InY2三种合金的体积模量、杨氏模量、剪切模量、泊松比和各向异性等力学性质,发现InY2合金的体积模量、杨氏模量、剪切模量要比其它两种的值大,其抗形变能力更强.本文还预测了In-Y金属间化合物的热力学性质,如德拜温度、热导率,通过第一性原理计算得到的In-Y金属间化合物的力学和热力学性质为In-Y合金材料的实际应用和材料设计提供了参考.

The mechanical stabilities,elastic and thermodynamic properties of In-Y intermetallic compounds(In-Y ICs)have been investigated by using a first-principles density functional theory(DFT)within ultrasoft pseudopotential plane-wave method.The lattice constants of In-Y ICs were calculated by the GGA-PBE method and compared with previous experimental date.It suggests that In-Y ICs are mechanically stable by analyzing the calculated elastic constants.Moreover,the elastic properties including shear modulus,Young’s modulus,bulk modulus,ratio B/G and elastic anisotropy are derived from the elastic data Cij.Compared with InY and In3Y,InY2 has the largest bulk modulus and the strongest anti-deformation ability in this work.In addition,according to the calculated ratio G/B and the Poisson’s ratio values,it was found that these In-Y ICs are ductile materials,and the ductile of In-Y ICs rank as follows:In3Y>InY>InY2.Finally,Debye temperature and thermal conductivity have been predicted through different empirical formulas.These results have an important reference value for the design and application of In-Y ICs in the future.