四元Heusler合金VFeScP/Ag(100)异质结的结构、磁性以及电子性质

Structural,magnetic and electronic properties of quaternary Heusler alloy heterojunction VFeScP/Ag(100)

基于密度泛函理论的第一性原理计算,研究了四元Heusler合金VFeScP/Ag(100)异质结的ScP-Ag、VFe-Ag、FeFe-Ag、VV-Ag、ScSc-Ag和PP-Ag这6种原子端面的结构、原子磁性、态密度和自旋极化.结果表明,由于界面原子复杂的相互作用,界面原子层呈现不同程度不平整,从而可能加剧界面层的电子散射.与块体相比,界面原子的配位数变化引起的d电子局域性和磁直接交互的共同作用,导致了的界面原子复杂的磁行为.电子态密度研究发现,原来块体中的高自旋极化率已经被破坏.最大的自旋极化率出现在ScSc-Ag异质结构中,约为53%,预测在自旋阀中有一定的应用潜力.

By using the first-principle calculation,the interface structures,atom-resolved magnetisms,densities of states,and spin polarizations of six atomic terminations,including ScP-Ag,VFe-Ag,FeFe-Ag,VV-Ag,ScSc-Ag and PP-Ag,in the quaternary Heusler alloy VFeScP/Ag(100)heterojunction were studied.The results show that due to different interface interactions,several rough atomic interface layers can be observed,which may lead to fierce spin electron scattering at the interface layer.By compared with the bulk,the d-electron localization effect originating from the change of coordination number of the interface atoms and direct magnetic exchange will together lead to complex atomic magnetic behavior in heterojunction.It is found that the high spin polarization in bulk has been destroyed.The largest spin polarization is about 53%from the ScSc/AgAg heterostructures,which may be of some value in spin valve devices applications.