Advanced materials for magnetic cooling: Fundamentals and practical aspects

TLDR

Research on magnetocalorics has surged, uncovering many intermetallic and oxide materials, yet only a few have been industrially scalable, and existing reviews focus mainly on ΔTad and ΔS, which are insufficient for assessing large‑scale applicability. The review aims to examine both the fundamental properties of recent magnetocaloric materials and their thermodynamic performance in functional devices. The authors review key material families (Gd₁₋ₓRₓ alloys, LaFe₁₃₋ₓSiₓ, MnFeP₁₋ₓAsₓ, R₁₋ₓAₓMnO₃), discuss practical aspects such as mechanical stability, synthesis, and corrosion, identify control parameters, propose models to achieve desired magnetocaloric properties, and introduce rotating and multilayered magnetocaloric concepts.

Abstract

Over the last two decades, the research activities on magnetocalorics have been exponentially increased, leading to the discovery of a wide category of materials including intermetallics and oxides. Even though the reported materials were found to show excellent magnetocaloric properties on a laboratory scale, only a restricted family among them could be upscaled toward industrial levels and implemented as refrigerants in magnetic cooling devices. On the other hand, in the most of the reported reviews, the magnetocaloric materials are usually discussed in terms of their adiabatic temperature and entropy changes (ΔTad and ΔS), which is not enough to get more insight about their large scale applicability. In this review, not only the fundamental properties of the recently reported magnetocaloric materials but also their thermodynamic performance in functional devices are discussed. The reviewed families particularly include Gd1-xRx alloys, LaFe13-xSix, MnFeP1-xAsx, and R1-xAxMnO3 (R = lanthanide and A = divalent alkaline earth)–based compounds. Other relevant practical aspects such as mechanical stability, synthesis, and corrosion issues are discussed. In addition, the intrinsic and extrinsic parameters that play a crucial role in the control of magnetic and magnetocaloric properties are regarded. In order to reproduce the needed magnetocaloric parameters, some practical models are proposed. Finally, the concepts of the rotating magnetocaloric effect and multilayered magnetocalorics are introduced.