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

• Published in: Physical review. B 2021-02, Vol.103 (5), p.1, Article 054414
• Main Authors: Buchelnikov, Vasiliy D., Sokolovskiy, Vladimir V., Miroshkina, Olga N., Baigutlin, Danil R., Zagrebin, Mikhail A., Barbiellini, Bernardo, Lähderanta, Erkki
• Format: Article
• Language: English
• Subjects: Contraction; Crystal lattices; Cubic lattice; Density functional theory; Ferromagnetism; Heusler alloys; Jahn-Teller effect; Martensite; Phase transitions; Spintronics
• ISSN: 2469-9950; 2469-9969
• DOI: 10.1103/PhysRevB.103.054414

We propose a ferromagnetic Heusler alloy that can switch between a metal and a half-metal. This effect can provide tunable spintronics properties. Using the density functional theory with reliable implementations of the electron correlation effects, we find Mn2 ScSi total energy curves consisting of distinct branches with a very small energy difference. The phase at low lattice crystal volume is a low magnetic half-metallic state while the phase at high lattice crystal volume is a high magnetic metallic state. We suggest that the transition between half-metallic and metallic states can be triggered by a triaxial contraction/expansion of the crystal lattice or by an external magnetic field 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 the presence of Jahn-Teller active 3d electrons on the Mn atoms.