Manganese- Copper- Gallium Alloys for Sustainable Refrigeration Through a Synergistic Study of Magnetocaloric and Mechanical Behavior

Emerging solid-state refrigeration holds great promise for improving energy efficiency and reducing greenhouse gases, thereby supporting sustainable systems. However, the challenge lies in identifying magnetocaloric materials that possess the necessary properties for real-world applications. Currently, there is a scarcity of materials that exhibit the ideal combination of magnetocaloric effects, mechanical properties, and minimal thermal hysteresis, which are essential for practical applications. The present study explores Mn-Cu-Ga-based alloys for magnetocaloric applications to address all three challenges. Alloy compositions are selected based on CALculation of PHAse diagrams calculations and experimental evaluation of magnetocaloric and mechanical properties. The optimal change in magnetic entropy is 2.84 J kg⁻¹-K⁻¹, and refrigeration capacity is 115.2 J kg⁻¹ at a 2 Tesla magnetic field. The thermal hysteresis, a factor that enhances the practical viability of the investigated alloys, is 1 K. Mechanical testing is performed to explore the ductile behavior of the investigated alloys. The strain-hardening exponent (n) indicates that the ductility is between 0.30 and 0.38, indicating a ductile nature. To support the experimental findings, first-principles calculations are performed. This dual approach, combining experimental and theoretical methods, offers a comprehensive understanding of Mn-Cu-Ga alloys for magnetocaloric applications.