MM′X型磁相变材料的若干研究进展

Recent progress in MM′X-type magnetic phase transition materials

在向绿色可持续发展目标迈进的过程中,能效比低且排放温室气体的传统气体压缩制冷技术面临较大环保压力。基于磁热效应的磁制冷技术绿色而高效,是新型固态制冷领域中具有较大实用化潜力的一种。磁制冷技术的核心是寻找成本低廉、无毒害、制冷区间大以及制冷效率高的制冷工质材料。近年来,具有马氏体相变的MM′X型化合物由于其较宽的相变调节温区和较高的磁热效应而颇受关注,成为磁致冷材料领域内研究的热点之一。国内外学者在优化MM′X体系性能及通过不同方式实现其磁结构耦合方面已经取得了令人瞩目的成果。将在简要回顾MM′X体系发展历程的基础上,着重介绍几个新的研究动向,包括双晶位掺杂调节相变、稀土元素替代、引入d-d杂化效应以及应对MM′X体系的粉末化问题等内容。

Durning the green and sustainable development,the traditional gas compression refrigeration technology with low energy efficiency and greenhouse gas emission faces enormous pressure in view of environmental protection.Magnetic refrigeration technology based on the magnetocaloric effect has high energy efficiency and environmentally friendly.It is a new kind of solid-state refrigeration technology with great practical potential.The critical topic of magnetic refrigeration is to find MCE materials with low cost,no toxicity,large refrigeration range and high refrigeration efficiency.MM′X compounds with martensitic transformation have attracted much attention recently owing to their wide temperature range of phase transition and sizeable MCE.Remarkable achievements have been made in realizing its magnetostructural coupling in different ways and optimizing the performance of MM′X system.Based on a brief review of the development of MM′X system,this paper focuses on several new research trends,including related works on modulation of phase transition by two-sites doping or rare-earth-element substitution,the effect of d-d hybridization,and the attempt to solve the pulverization problem of MM′X system.