A perspective magnetic bed comprising Gd alloy multi-microwires for energy-efficient magnetic refrigeration

TL;DR

This paper introduces a novel magnetic bed structure using Gd alloy microwire arrays with different Curie temperatures, achieving a table-like magnetocaloric effect suitable for energy-efficient magnetic refrigeration.

Contribution

The study designs a new magnetic bed with tailored magnetocaloric properties using Gd alloy microwires, demonstrating enhanced heat transfer and refrigerant capacity for refrigeration applications.

Findings

Achieved a smooth table-like magnetic entropy change over 92-107 K.

Maximum entropy change of ~9.42 Jkg$^{-1}$K$^{-1}$ at 5 T.

Refrigerant capacity of ~676 Jkg$^{-1}$ at 5 T.

Abstract

We have designed a new magnetic bed structure with desirable table-like magnetocaloric effect (MCE) by using three kinds of soft ferromagnetic Gd-Al-Co microwire arrays with different Curie temperatures ($T_C$). The $T_C$ interval of these three wires is ~10 K and the designed new structure named Sample A. This sample shows a smooth table-like magnetic entropy change ($\Delta S_M$) at high applied field change ($\mu_0 \Delta H=5 T$) ranging from ~92 K to ~107 K. The maximum entropy change ($-\Delta S_M^{\rm max}$) and refrigerant capacity (RC) for Sample A at $\mu_0 \Delta H=5 T$ are calculated to be ~9.42 Jkg$^{-1}$K$^{-1}$ and ~676 Jkg$^{-1}$. The calculated curves of $-\Delta S_M(T)$ and the corresponding experimental data match well with each other, suggesting that the desirable magnetocaloric properties of the microwire arrays can be designed. Simulation shows that the RC values of the designed systems increase when increasing the interval of $T_C$. The table-like MCE and the enhanced heat-transfer efficiency due to the enhanced surface areas of the microwires make this newly designed magnetic bed very promising for use in energy-efficient magnetic refrigerators.