Reducing Energy Waste by Tuning Martensite in Heusler Alloys

Heusler alloys are widely studied due to their potential for practical applications, making use of their martensitic transformations. However, hysteresis is a long-standing drawback that reduces the chance of transferring these alloys from the laboratory to industry. In this work, we studied a Cr-doped Ni2MnGa-based material designed by integrating data obtained from the previous phase and hysteresis diagrams taken from the literature, reaching Ni2.15Mn0.70Cr0.15Ga. The compound presents a magnetostructural transition at room temperature, with a ferromagnetic martensite phase, and moderate thermal hysteresis of approximately 4 K. The magnetocaloric effect was explored, showing a reversible entropy change higher than 8 Jkg- 1K(-1) under 0-5 T field change, an advance towards high reversibility for this family alloys.