弹热效应是磁相变材料展现的新功能之一，因其在环保高效的固态制冷技术中具有潜在应用而成为凝聚态物理和材料领域的研究热点。本项目以新型高韧性的d-metal Heusler磁相变合金NiMnTi(Co)为研究对象，以马氏体相变晶体学理论和铁磁学理论为基础，针对其相变路径对材料自身相变特征和所受应力、温度、磁场等外界物理环境激励的依赖关系，研究不同相变路径的发生条件及其对于绝热温变、相变临界应力、滞后损耗等弹热性能的影响机制，以期在NiMnTi(Co)合金中获得大弹热效应。本项目将为深入理解影响弹热效应的关键因素和提高磁相变合金弹热效应的制冷能力和相变可逆性提供科学基础。

Elastocaloric effect is one of emerging functionalities of magnetic phase transformation materials. Due to its potential applications in the efficient and eco-friendly solid-state cooling devices, elastocaloric effect has attracted a lot of attention in the field of condensed matter physics and material science. We observed that different stress loading condition, ambient temperature, magnetic field and intrinsic phase transformation features of the alloys result in different crystal structures of martensite, consequently in different martensitic transformation paths in d-metal Heusler alloys NiMnTi(Co). This proposal aims to reveal the underlying mechanism of influence of martensitic transformation path on the elastocaloric effect including adiabatic temperature change, critical stress, hysteresis and reversibility, on the basis of the theories of martensitic transformation and ferromagnetics. Moreover, this proposal intends to enhance the elastocaloric effect of NiMnTi(Co) alloys. The results of this project will be of important significance in terms of in-deep understanding of the key factor affecting elastocaloric effect of magnetic martensitic transformation materials and provide important references for enhancing the elastocaloric effect in magnetic phase transformation materials.