Co${}_2$PtGa: A promising magnetic shape memory alloy with high martensite transition temperature

In the present work, a combined theoretical and experimental study on Co${}_2$PtGa Heusler alloy shows that it exhibits a martensite transition around 1320 K with a small thermal hysteresis (10 K). Dynamical stability of Co${}_2$PtGa in the tetragonal phase has been established by the theoretically calculated phonon dispersion curves. Magnetization measurements suggest that this alloy is a ferromagnetic material with a saturation magnetic moment of 2.83 ${\mu }_B$/f.u. at 2 K, which is in excellent agreement with the value obtained from $\mathit{\text{ab-initio}}$ calculations (2.87 ${\mu }_B$/f.u.). Our present study demonstrates that Co${}_2$PtGa is a promising material for high temperature magnetic shape memory application.