Recent Progress in Magnetoelastic Fe2P-type Materials for Magnetocaloric Cooling

Solid-state magnetocaloric cooling attracts increasing attention as a novel technique for its high efficiency in energy conversion and its sustainability. Several high-quality magnetocaloric materials (MCMs) have been found, but among these MCMs, (Mn,Fe)₂(P,Si)-based materials are one of the most promising candidates for its giant magnetocaloric effect (GMCE), noncritical components, and tuneable Curie temperature (T_C) around room temperature. To further accelerate its practical market applications, a lot of studies have been made to enhance the GMCE, tune T_C, and reduce the thermal hysteresis (ΔT_hys). This review mainly focuses on introducing the latest efforts to optimize the GMCE performance of this material family, including doping with different elements, microstructural improvements, and practical manufacturing techniques. Besides that, we further suggest possible approaches to boost the material engineering and highlight promising efforts of applying machine learning in the search for the optimal composition and structure of (Mn,Fe)₂(P,Si)-based MCMs. This bridges the gap between fundamental research and engineering to advance the magnetocaloric energy conversion technology closer to real applications.