A detailed theoretical study of the structural and elastic properties of magnesium silicide Mg2 Si under isotropic lattice deformation has been performed based on the first-principles' pseudopotential method. The ...A detailed theoretical study of the structural and elastic properties of magnesium silicide Mg2 Si under isotropic lattice deformation has been performed based on the first-principles' pseudopotential method. The results show that isotropic lattice deformation from 94% to 106% results in a linear decrease in the energy gap for the direct Г15-Г1 and indirect Г15-L1 transitions, while the indirect band gap Г15 -X1 increases within a range of 94%-104%, and then reduces over the range of 104%. Additionally, isotropic lattice deformation from 94% to 106% also causes a decrease in the elastic constants and modulus of Mg2 Si. Furthermore, Mg2 Si with lattice deformation from 94% to 106% is brittle, being most brittle at 94% lattice constant.展开更多
基金supported by the Young Talents Training Project of Guizhou Province (Grant No. [2012]152)the National Natural Science Foundation of Guizhou Province (Grant No. [2011]2323)+5 种基金the Introducing Talents Foundation for the Doctor of Guizhou University (Grant No.[2010]032)the National Natural Science Foundation of China (Grant No.61264004)the Special Fund for International Cooperation of the Ministry of Science and Technology of China (Grant No. 2008DFA52210)the Key SciTech Research Project of Guizhou Province of China (Grant No.[2011]3015)the Special Fund for Construction of SciTech Innovative Talents Team of Guizhou Province of China (Grant No. [2011]4002)the Fund for International SciTech Cooperation of Guizhou Province of China (Grant No. [2012]7004)
文摘A detailed theoretical study of the structural and elastic properties of magnesium silicide Mg2 Si under isotropic lattice deformation has been performed based on the first-principles' pseudopotential method. The results show that isotropic lattice deformation from 94% to 106% results in a linear decrease in the energy gap for the direct Г15-Г1 and indirect Г15-L1 transitions, while the indirect band gap Г15 -X1 increases within a range of 94%-104%, and then reduces over the range of 104%. Additionally, isotropic lattice deformation from 94% to 106% also causes a decrease in the elastic constants and modulus of Mg2 Si. Furthermore, Mg2 Si with lattice deformation from 94% to 106% is brittle, being most brittle at 94% lattice constant.
