Half-metallic Heusler alloy/AlP based magnetic tunnel junction

Exploring the spin transport characteristics of magnetic tunnel junctions based on half-metallic Heusler holds significance, not only in unraveling the fundamental physics at play but also in advancing applications of spintronic devices. Here, density functional theory in conjunction with non-equilibrium Green’s functions has been systematically employed to investigate two prominent Heusler alloys, Co2CrAl and CoFeCrAl, which are of direct interest to the candidates of magnetic tunnel junction. The electronic structures of two Hesler alloys reveal that both exhibit characteristics of half-metallic ferromagnets, featuring a substantial spin-down bandgap and achieving 100% spin polarization. The tunneling magnetoresistance ratios obtained for Co2CrAl/AlP/Co2CrAl and CoFeCrAl/AlP/CoFeCrAl magnetic tunnel junctions are determined to be 173% and 59%, respectively, with the former exhibiting superior device characteristics. Therefore, the Co2CrAl/AlP-based magnetic tunnel junction demonstrates ideal performance, providing new opportunities for two-dimensional spintronics.