Designing magnetic compensated states in tetragonal Mn3Ge-based Heusler alloys

Magnetic compensated materials attracted much interests due to the observed large exchange bias and large coercivity, and also their potential applications in the antiferromagnetic spintronics with merit of no stray field. In this work, by using ab-initio studies, we designed several Ni (Pd, Pt) doped Mn3Ge-based D022-type tetragonal Heusler alloys with fully compensated states. Theoretically, we find the total moment change is asymmetric across the compensation point (at ~x=0.3) in Mn3-xYxGe (Y=Ni, Pd, Pt). In addition, an uncommon discontinuous jump is observed across the critical zero-moment point, indicating that some non-trivial properties may emerge at this point. Further electronic analyses of these compensated alloys reveal high spin polarizations at the Fermi level, which is advantageous for spin transfer torque applications.