A spin-gapless semiconductor of inverse Heusler Ti2CrSi alloy: First-principles prediction

• Ti2CrSi exhibits antiferromagnetic semiconductor → SGS → half-metal → nonmagnetic semiconductor (or conventional ferrimagnet) transitions with lattice distortions.
• Ti2CrSi is an SGS at −2.2% and +11.6% uniform strains and at ±1.8% tetragonal distortions.
• Ti2CrSi shows a half-metallic feature up to −5.3%(+11.6%) for negative(positive) uniform strain.
• Ti2CrSi is a half-metal up to -9.3%(+13.2%) for squeezed(elongated) tetragonal distortion.

Spin-gapless semiconductors (SGSs) have been recently identified as a new class of materials that have potential applications in spintronic devices. On the basis of first-principles calculations, an inverse Heusler Ti2CrSi alloy is predicted as a promising candidate for SGS. The Ti2CrSi alloy with equilibrium lattice parameter is an antiferromagnetic semiconductor with a total magnetic moment that satisfies the Mt=Zt−18Mt=Zt−18 rule. Ti2CrSi exhibits antiferromagnetic semiconductor→SGS→half-metallicantiferromagnet→nonmagneticsemiconductor→SGS→half-metallicantiferromagnet→nonmagnetic semiconductor (or conventional ferrimagnet) transitions under lattice distortions. Ti2CrSi achieves an SGS feature at −2.0% and +11.4% uniform strains and at ±1.8% tetragonal distortions. SGS to half-metallic antiferromagnet transitions occur at −2.4% and +11.8% uniform strains and at ±2.2% tetragonal distortions. The half-metallic feature persists up to −5.3% and +13.5% uniform strain, as well at −9.3% and +13.2% squeezed and elongated tetragonal distortions. Ti2CrSi is a nonmagnetic semiconductor at a uniform strain of less than −5.3% and is a conventional ferrimagnet at larger than +13.5% uniform strain. Moreover, beyond −9.3% to +13.2% tetragonal distortion range, the alloy behaves as a conventional ferrimagnet. With its diverse electronic and magnetic properties, Ti2CrSi makes a promising candidate for spintronic applications.