具有大半金属能隙的V掺杂LiZnP新型稀磁半导体的磁电性质

Magnetoelectric properties of V doped LiZnP new diluted magnetic semiconductor with large half metallic energy gap

采用基于密度泛函理论的第一性原理平面波超软赝势法,对新型稀磁半导体Li1±y(Zn1-xVx)P(x=0,0.0625;y=0,0.0625)体系进行几何结构优化,计算并分析了各体系的电子结构,形成能,半金属性,磁性及居里温度。结果表明,新型稀磁半导体LiZnP可通过掺入V和改变Li的化学计量数来实现自旋和电荷注入机制的分离。单掺V引入了自旋极化杂质带,表现出强的半金属性,sp-d杂化导致体系产生2.92 μB的净磁矩。体系的性质还受Li的化学计量数的影响,Li空位时,半金属性和磁性有所减弱,但居里温度最高;Li填隙时,杂化作用增强,形成能最低,导电能力最强,磁性最大。

In this paper, the geometry structures of Li1±y(Zn1-xVx)P (x=0, 0.0625;y=0, 0.0625) were optimized by adopting the first-principles calculation of plane wave ultra-soft pseudo-potential technology based upon the density function theory. Then the electronic structures, formation energies, half metallicity, magnetism and optical properties were calculated and analyzed. The results reveal that the separation of spin and charge injection mechanisms could be achieved in LiZnP semiconductor, and the magnetic and electrical properties of diluted magnetic semiconductor would be regulated respectively by V doping and Li stoichiometry. The spin polarized impurity band introduced by single doping V showed strong half-metallicity, and sp-d orbital hybridization made the system have 2.92 μB magnetic moment. And the properties of the systems were also influenced by the stoichiometry of Li. In the Li-deficiency compounds, the half metallicity and magnetism became weakened, while the Curie temperature was the highest. But for the Li-excess compounds, the hybridization was enhanced, the forming energy was the lowest, and the conductivity and magnetism were the strongest because of the enhancing of sp-d hybridization.