Half-metallic behavior and magnetic properties of various (001) surfaces for the Heusler alloy Y2CrSn

Abstract

In this study, the half-metallic behavior and magnetic properties of various (001) surfaces for Y2CrSn Heusler alloy were investigated using the spin-polarized first-principles method. The spin polarizations of the standard stable YSn-terminated and artificial stable SnSn-terminated (001) surfaces were −96.9% and −95.8%, respectively, using the generalized gradient approximation (GGA) method (−69.2% and −83.0% using the GGA + U method), and thus the two surfaces have potential use in spintronic devices. The spin polarizations of the standard YCr-terminated, artificial YY-terminated, and artificial CrCr-terminated (001) surfaces were only −43.0%, 29.3%, and −40.8%, respectively, using the GGA method (−63.2%, −67.9%, and −44.4% using the GGA + U method). The atomic magnetic moments (AMMs) of the Y and Cr atoms in the outmost layer changed greatly due to the surface states, but little change was found in the AMMs of atoms near the central layer. The average AMMs obtained for the Sn, Y, and Cr atoms using the GGA + U method were only slightly larger than the corresponding AMMs determined using the GGA method.