The Magnetocaloric Behaviors of Gd-based Microwire Arrays with Different Curie Temperatures

The desirable table-like magnetocaloric effect (MCE) was obtained by designing a new magnetic bed, which comprises three kinds of Gd-based microwire arrays with different Curie temperatures (T_C). The T_C interval among these wires is ~10 K. This new magnetic bed shows a smooth ferromagnetic to paramagnetic transition at ~100 K. In addition, a table-like magnetic entropy change (ΔS_M) was obtained, ranging from ~92 K to ~107 K, with a maximum entropy change (−ΔS_M^max) of 9.42 J/kgK for a field change (μ₀ΔH) of 5 T. Notably, the calculated results of −ΔS_M(T) corresponded to the experimental data for μ₀ΔH = 5 T, suggesting that a microwire array-based magnetic bed with desirable magnetocaloric response can be designed. In addition, it was shown that a larger table-like temperature range and cooling efficiency can be achieved by increasing the interval of T_C among microwire arrays. These important findings indicate that the newly designed magnetic bed is very promising for active magnetic cooling technology.