Prediction of a Heusler alloy with switchable metal-to-half-metal behavior

TL;DR

This paper predicts a ferromagnetic Heusler alloy capable of switching between metallic and half-metallic states, enabling tunable spintronics applications through lattice or magnetic field manipulation.

Contribution

It introduces a novel Mn2ScSi Heusler alloy with switchable electronic and magnetic phases based on density functional theory calculations.

Findings

Low volume phase is a half-metallic state.

High volume phase is a metallic state.

Transition can be triggered by lattice changes or magnetic field.

Abstract

We propose a ferromagnetic Heusler alloy that can switch between a metal and a half-metal. Thiseffect can provide tunable spintronics properties. Using the density functional theory (DFT) withreliable implementations of the electron correlation effects, we find Mn2ScSi total energy curvesconsisting of distinct branches with a very small energy difference. The phase at low lattice crystalvolume is a low magnetic half-metallic state while the phase at high lattice crystal volume is a highmagnetic metallic state. We suggest that the transition between half-metallic and metallic statescan be triggered by a triaxial contraction/expansion of the crystal lattice or by an external magneticfield if we assume that the lattice is cubic and remains cubic under expansion/contraction. However,the phase at high volume can also undergo an austenite-martensite phase transition because of thepresence of Jahn-Teller active3delectrons on the Mn atoms.