Geometrically Engineered Magnetocaloric Microwire Arrays for Magnetic Cooling Applications

Magnetocaloric wire-shaped materials for magnetic refrigeration hold great promise for next-generation cooling technologies due to their high cooling efficiency and strong geometric effects. Our recent findings of a large magnetocaloric effect (MCE) in melt-extracted Gd-alloy microwires have opened new avenues for realizing this approach. In this study, we present a novel strategy for designing soft ferromagnetic microwire assemblies (e.g., Gd 55 Al 20 Co 25 ) in both single-layer and multilayer configurations with precisely controlled geometry, enabling enhanced cooling efficiency of the magnetic refrigerant through systematic wire arrangement. Experimental results reveal larger MCEs in laminated microwire structures compared with a single microwire, arising from strong wire–wire and layer–layer magnetic interactions. These interlayer magnetic couplings are found to play an important role in determining the MCE magnitude. Notably, even-layer laminates exhibit substantially enhanced MCE values (−Δ S m ≈ 9.86 J kg -1 K -1 ) relative to odd-layer structures (−Δ S m ≈ 8.56 J kg -1 K -1 ) under an applied field of 5 T. These geometrically engineered microwire laminate architectures show promising potential for energy-efficient magnetic refrigeration applications.