Effect of Mn concentration on the phase transformation in Ni–Mn–Ga single crystal

Aim of this paper is to study the transformation temperature of Ni–Mn–Ga single crystals by using differential scanning calorimetry. It shows that martensitic temperature abruptly increase with increasing Mn concentration whereas Curie transition to decrease. The calculated value of electron-to-atom ratio (e/a) reveal that it increases with increased doping of Mn in place of Ga at fixed Ni content. The crystal structures at room temperature were studied using XRD pattern. Thermo-magnetic behavior of the Ni–Mn–Ga alloy shows the ferromagnetic nature and its behaviour is slightly losing due to antiferromagnetic ordering of excess Mn atoms. Microstructure from SEM image confirm that the alloys are martensitic plates. The martensitic plates contain fewer stripes like magnetic domains.