Recent progress in exploring magnetocaloric materials

TL;DR

This paper reviews recent advances in magnetocaloric materials, focusing on LaFe13-xSix alloys with large entropy changes near room temperature, and discusses factors affecting their magnetic properties for refrigeration applications.

Contribution

It provides a comprehensive review of the development and understanding of magnetocaloric materials, especially LaFe13-xSix alloys, highlighting new findings on their magnetic transition and effects of doping and pressure.

Findings

LaFe13-xSix alloys exhibit large entropy changes near room temperature.

Magnetic rare-earth doping and pressure significantly influence MCE properties.

Effective methods to evaluate MCE in first-order magnetic transition materials are discussed.

Abstract

Magnetic refrigeration based on the magnetocaloric effect (MCE) of materials is a potential technique that has prominet advantages over the currently used gas compression-expansion technique in the sense of its high efficiency and environment friendship. In this article, our recent progress in explorating effective MCE materials is reviewed with the emphasis on the MCE in the LaFe13-xSix-based alloys with a first order magnetic transition discovered by us. These alloys show large entropy changes in a wide temperature range near room temperature. Effects of magnetic rare-earth doping, interstitial atom, and high pressure on the MCE have been systematically studied. Special issues such as appropriate approaches to determining the MCE associated with the first-order magnetic transition, the depression of magnetic and thermal hystereses, and the key factors determining the magnetic exchange in alloys of this kind are discussed. The applicability of the giant MCE materials to the magnetic refrigeration near ambient temperature is evaluated. A brief review of other materials with significant MCE is also presented in the article.