Magnetic properties and magnetocaloric effects of rare-earth based high-entropy amorphous microwires

Abstract

The development of efficient and environmentally friendly solid-state refrigeration materials is a key issue in magnetic refrigeration technology. Rare-earth based high-entropy alloys with good magnetocaloric effect have been recently recognized as good candidates for magnetic refrigeration. Herein, the magnetic properties and the magnetocaloric performance of the equiatomic Er20Gd20Dy20Co20Al20 high-entropy microwires by melt-extraction and have been investigated systematically. The melt-extraction Er20Gd20Dy20Co20Al20 microwires were confirmed to exhibit a fully amorphous structure and good glass-forming ability. The Er20Gd20Dy20Co20Al20 amorphous microwires undergo a second order phase transition around 43 K from ferromagnetic to paramagnetic state. Notably, the Er20Gd20Dy20Co20Al20 high-entropy amorphous microwires exhibit significant low-temperature magnetocaloric effect and excellent performance, characterized by a magnetic entropy change of 9.11 J kg⁻1 K⁻1 and a refrigerant capacity of 515.3 J kg⁻1. These values are comparable to many recently reported low-temperature magnetocaloric materials. This makes the Er20Gd20Dy20Co20Al20 amorphous microwires promising candidates for low temperature solid-state magnetic refrigeration applications, providing new ideas for the design and application of efficient and environmentally friendly refrigeration materials.

Keywords

• High-entropy alloys
• Amorphous
• Magnetocaloric effect
• Low temperature
• Magnetic refrigeration