  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 \textit{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.
