The structural, magnetic and magnetocaloric properties of Ni ₂ Mn _{1+ x} In _{1− x} alloys, prepared using an arc-melting furnace in an argon environment, have been studied for their potential application in cost-effective magnetic refrigeration technology. The room-temperature x-ray diffraction shows that the Ni ₂ Mn _{1+ x} In _{1− x} alloys with 0 ⩽ x ⩽ 0.34 exhibit austenite cubic phase, whereas the alloys with x > 0.34 have mixed tetragonal martensite and cubic austenite phases. The Ni ₂ Mn _1.34 In _0.66 alloy shows a clear second-order phase transition with a Curie temperature of 305 K but its elemental composition is very close to the critical composition between first and second–order phase transitions. The calculated magnetic entropy change and relative cooling power of the Ni ₂ Mn _1.34 In _0.66 alloy measured at 3 T field are 4.5 J kg ⁻¹ K ⁻¹ and 201 J kg ⁻¹ , respectively. The temperature dependent resistivity of Ni ₂ Mn _1.34 In _0.66 alloy measured at H = 0 Oe shows that the sample has a room temperature resistivity of 7 The absence of thermal and magnetic hysteresis due to second-order magnetic phase change, coupled with higher values of magnetic entropy change and relative cooling power, suggests that the Ni ₂ Mn _1.34 In _0.66 alloy has the potential for magnetic refrigeration.

We performed combined theoretical and experimental studies of electronic, structural, and magnetic properties of Fe₂MnSn Heusler alloy. The density functional theory calculation shows that the Fe₂MnSn alloy has two energetically close phases, namely, hexagonal D0₁₉ and cubic L2₁, which agrees well with the experimental results. Both the hexagonal and cubic phases are ferromagnetic, with large magnetization values of about 6 μ_B/f.u. and high Curie temperature above room temperature. The hexagonal phase shows high magnetic anisotropy of 5.1 Merg/cm³. These findings may be interesting for magnetic applications where large saturation magnetization, high Curie temperature, and high magnetic anisotropy are desired.

Half-metallic Heusler alloys have been intensively studied in recent years due to their potential applications in spin-based devices, e.g., in magnetic tunnel junctions. Yet, their properties may be very sensitive to the choice of the substrates, i.e., to the epitaxial strain and interface properties. Here, we report the results of our computational work on the half-Heusler compound CrMnSb_(1−x)P_x. In particular, we demonstrate that the parent compound CrMnSb is close to a half-metallic material at the optimized lattice parameter, with the onset of the half-metallic bandgap a few meV above the Fermi energy. Moreover, although it undergoes a half-metallic transition under a uniform compression of ∼1.5%, such a transition is absent under epitaxial strain. At the same time, we show that a half-metallic transition could be induced by a chemical substitution of Sb with P, which results in a volume reduction of the unit cell. In particular, 50% substitution of Sb with P leads to a robust half-metallicity in CrMnSb_(1−x)P_x, with 100% spin polarization being retained at a large range of epitaxial strain. Thus, our results indicate that CrMnSb_0.5P_0.5 could be grown on different types of substrates, e.g., GaAs, without its electronic properties being detrimentally affected by biaxial strain. In addition, CrMnSb_0.5P_0.5 exhibits a fully compensated ferrimagnetic alignment, which could be potentially useful in applications where stray magnetic fields are undesirable.