反Heusler合金Ti_2Ru_(1-x)Fe_xSn半金属磁性的第一性原理研究

本文基于第一性原理,通过对反Heusler合金Ti_2RuSn的Y位进行Fe元素掺杂,来探究其掺杂前后的相关特性及掺杂机理,以便寻求半金属性更稳定的Heusler合金材料,为后续相关理论研究及实验提供一定参考.在掺杂过程中随着Fe元素掺杂浓度的增加,反Heusler合金Ti_2RuSn的半金属性并未受到破坏,其带隙反而随掺杂浓度逐渐变宽,从未掺前的0.451 eV展宽到了全掺杂的0.711 eV.为分析掺杂体系的稳定性,我们计算了它们相对于理想反Heusler合金Ti_2RuSn块体的形成能,结果表明,对反Heusler合金Ti_2RuSn的Y位进行Fe元素掺杂可以展宽其带隙,并且掺杂浓度越低,体系相对较容易形成.

First-Principles study on half-metallicity and magnetism of the inverse Heusler compound Ti2Ru1-xFexSn

The first-principles calculations within the DFT are performed to investigate the doping effects on the electronic and magnetic properties of inverse Heusler compound Ti2RuSn. Compounds derived from doping all possess half-metallicity and the spin gap becomes wider with the increase of the doping concentration. It increases from 0.451 eV in the ideal bulk to 0.711 eV at the case of x=1. To study the stability of the systems, we also calculate their formation energies, the results exhibit that the Y-site doping of inverse Heusler alloy Ti2RuSn can broaden the spin gap, and the system is easier to form at the lower doping concentration.