Search for half-metallic ferrimagnetism in V-based Heusler alloys Mn$_2$VZ (Z$=$Al, Ga, In, Si, Ge, Sn)

TL;DR

This study investigates Mn$_2$V-based full Heusler alloys, demonstrating that slight lattice expansion and minimal atomic disorder can induce and preserve half-metallic ferrimagnetism, promising for spintronic applications.

Contribution

It reveals that small lattice expansion and atomic disorder can restore and maintain half-metallic ferrimagnetism in Mn$_2$VZ alloys, advancing their potential use in spintronics.

Findings

Small lattice expansion restores half-metallic ferrimagnetism.

Atomic disorder preserves high spin polarization.

Alloys maintain Slater-Pauling behavior despite disorder.

Abstract

Using a state-of-the-art full-potential electronic structure method within the local spin density approximation, we study the electronic and magnetic structure of Mn$_2$V-based full Heusler alloys: Mn$_2$VZ (Z=Al, Ga, In, Si, Ge, and Sn). We show that small expansion of the calculated theoretical equilibrium lattice constants restores the half-metallic ferrimagnetism in these compounds. Moreover a small degree of disorder between the V and Z atoms, although iduces some states within the gap, it preserves the Slater-Pauling behaviour of the spin magnetic moments and the alloys keep a high degree of spin-polarisation at the Fermi level opening the way for a half-metallic compensated ferrimagnet.