A full spectrum of spintronic properties demonstrated by a C1b-type Heusler compound Mn2Sn subjected to strain engineering

Abstract

Zero-gap half-metallic fully-compensated ferrimagnets (ZG-HM-FCFs) and fully-compensated ferrimagnetic spin-gapless semiconductors (FCF-SGSs) are promising candidates for spintronic applications due to the complete (100%) spin polarization of electrons around the Fermi level. Motivated by recent experimental and theoretical findings on binary Mn₂-based C1_b-type Heusler compounds, by means of first-principles calculations, we found that Mn₂Sn exhibits metallic ferrimagnetism properties. Most interestingly, at a uniform strain, there is a novel transition in the physics from a metallic ferrimagnet (MFi) to true ZG-HM-FCF, HM-FCF, and FCF-SGS, and then to a fully-compensated ferrimagnetic semiconductor (FCF-S). The binary Mn₂Sn compound remains as a MFi under tetragonal distortion, however. We also reveal that the structure of Mn₂Sn is stable, according to its mechanical properties, calculated cohesion energy, and formation energy. Our work demonstrates that Mn₂Sn is potentially an all-round candidate for spintronic applications because it shows a full spectrum of spintronic properties at a uniform strain.