Co$_{2}$PtGa: A promising magnetic shape memory alloy with high martensite transition temperature

TL;DR

This study combines theoretical and experimental methods to show that Co$_{2}$PtGa is a ferromagnetic shape memory alloy with a high martensite transition temperature around 1320 K, suitable for high-temperature applications.

Contribution

The paper provides the first combined theoretical and experimental analysis demonstrating Co$_{2}$PtGa's high martensite transition temperature and magnetic properties, highlighting its potential for high-temperature magnetic shape memory devices.

Findings

Martensite transition temperature around 1320 K.

Ferromagnetic with saturation magnetic moment of 2.83 μ_B/f.u.

Dynamically stable tetragonal phase confirmed by phonon calculations.

Abstract

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.