Low-dimensional magnetocaloric materials for energy-efficient magnetic refrigeration: Does size matter?

TL;DR

This paper reviews how low-dimensional magnetocaloric materials like thin films and nanostructures can enhance magnetic refrigeration efficiency, emphasizing the importance of size, geometry, and interface effects for practical device design.

Contribution

It provides a comprehensive overview of the influence of size and geometry on the magnetocaloric effect, guiding future material engineering for energy-efficient refrigeration.

Findings

Low-dimensional structures improve heat exchange and mechanical flexibility.

Size and interface effects significantly influence the magnetocaloric effect.

Guidelines for designing nanostructured magnetocaloric materials are proposed.

Abstract

The magnetocaloric effect (MCE) provides a promising foundation for the development of solid-state refrigeration technologies that could replace conventional gas compression-based cooling systems. Current research efforts primarily focus on identifying cost-effective magnetic materials that exhibit large MCEs under low magnetic fields across broad temperature ranges, thereby enhancing cooling efficiency. However, practical implementation of magnetic refrigeration requires more than bulk materials; real-world devices demand efficient thermal management and compact, scalable architectures, often achieved through laminate designs or miniaturized geometries. Magnetocaloric materials with reduced dimensionality, such as ribbons, thin films, microwires, and nanostructures, offer distinct advantages, including improved heat exchange, mechanical flexibility, and integration potential. Despite these benefits, a comprehensive understanding of how size, geometry, interfacial effects, strain, and surface phenomena influence the MCE remains limited. This review aims to address these knowledge gaps and provide guidance for the rational design and engineering of magnetocaloric materials tailored for high-performance, energy-efficient magnetic refrigeration systems.