Origin Of The Large Interfacial Perpendicular Magnetic Anisotropy In Mgo/Co2feal

Interfacial perpendicular magnetic anisotropy in the MgO/Co2FeAl heterostructure is desired for technological applications, while the origin of the large interfacial anisotropy constant K-i remains controversial. Here we show that, by modeling four types of interface models for the MgO/Co2FeAl system using first-principles calculations, the MgO/Co-2 interface is energetically more favorable than the MgO/FeAl interface and the interfacial Co atoms at the former interface produce out-of-plane while the interfacial Fe atoms at the latter interface produce in-plane The origin of these different behaviors can be explained by the atomic-resolved and orbital-resolved K-i along with the perturbation theory energy analysis. In addition, we also studied the influence of 26 capping layers on the interfacial magnetic anisotropy of MgO/Co2FeAl and found that Fe and W capping can significantly enhance K-i in the MgO/Co2FeAl with a particularly large K-i of 4.90 mJ/m(2) in the W-capped model. This work clarifies the atomistic origin of the interfacial perpendicular magnetic anisotropy and provides guidance to further enhance interfacial K-i by adding capping layers in the MgO/Co2FeAl.