Chemically Controllable Magnetic Transition Temperature and Magneto-Elastic Coupling in MnZnSb Compounds
Chemically Controllable Magnetic Transition Temperature and Magneto-Elastic Coupling in MnZnSb Compounds
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MnZnSb 化合物中化学可控磁转变温度和磁弹性耦合
DOI：
10.1002/adfm.202100108
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发表时间：
2021
影响因子：
19
通讯作者：
Murgatroyd P
中科院分区：
文献类型：
--
作者：
Murgatroyd P
与广泛使用的基于气体的系统相比，磁热材料提供了设计更环保的热管理设备的可能性。开发这种基于固态的技术的挑战在于难以找到在宽温度范围内表现出大磁热效应的材料以及合适的二次应用参数，如低热容量和高热导率。一系列衍生自PbFCl结构的化合物使用计算和实验方法的组合进行了研究，重点关注磁性和非磁性基态中的晶胞体积变化。磁性的标度分析确定它们是二阶相变铁磁体，并且磁熵变是由方网中的磁弹性应变通过中子和同步加速器X射线衍射确定的磁性转变的耦合驱动的。主要和次要的应用相关的属性进行了实验测量，和c/paradigm被确定为一个准确的代理，以控制磁过渡。方网上的化学取代提供了在252和322 K之间的宽温度范围内调谐居里温度。一个预测的机器学习模型的c/paradigm的开发，以指导未来的探索性合成。
Magneto‐caloric materials offer the possibility to design environmentally friendlier thermal management devices compared to the widely used gas‐based systems. The challenges to develop this solid‐state based technology lie in the difficulty of finding materials presenting a large magneto‐caloric effect over a broad temperature span together with suitable secondary application parameters such as low heat capacity and high thermal conductivity. A series of compounds derived from the PbFCl structure is investigated using a combination of computational and experimental methods focusing on the change of cell volume in magnetic and non‐magnetic ground states. Scaling analysis of the magnetic properties determines that they are second order phase transition ferromagnets and that the magnetic entropy change is driven by the coupling of magneto‐elastic strain in the square‐net through the magnetic transition determined from neutron and synchrotron X‐ray diffraction. The primary and secondary application related properties are measured experimentally, and thec/aparameter is identified as an accurate proxy to control the magnetic transition. Chemical substitution on the square‐net affords tuning of the Curie temperature over a broad temperature span between 252 and 322 K. A predictive machine learning model for thec/aparameter is developed to guide future exploratory synthesis.