Emergent properties in the natural composite Ni 2 MnSb 0.5 Al 0.5
Emergent properties in the natural composite Ni 2 MnSb 0.5 Al 0.5
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天然复合材料的新兴性能 Ni 2 MnSb 0.5 Al 0.5
DOI：
10.1088/1361-6463/ab7c9f
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Bhobe, P A
中科院分区：
文献类型：
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作者：
Samanta, Tamalika;Salas, D;Srihari, V;Karaman, I;Bhobe, P A
研究了Ni2MnSb0.5Al0.5Heusler合金的结构、输运和磁性能。用X射线衍射仪和扫描电子显微镜对Ni2MnSb0.5Al0.5进行了结构分析，证实Ni2MnSb0.5Al0.5是Ni2MnSb和Ni2MnAl相的天然复合体，而不受热处理条件的影响。该复合材料具有凝固相分离形成的树枝晶组织。用X射线近边吸收光谱证实了电子相分离，并用多重散射理论从头计算证实了电子相分离。通过记录Ni2MnSb0.5Al0.5Heusler合金的电阻率、热导率和热容等磁性和输运性质，对这种新型复合形式的Ni2MnSb0.5Al0.5Heusler合金进行了全面的表征。该体系的复合微结构在大幅度降低其导热系数的同时，保持了其金属特性，起到了至关重要的作用。与许多氧化物复合材料不同的是，Ni2MnSb0.5Al0.5的磁性不能看作两相特性的体积平均，而是表现出长范围的铁磁有序，居里温度为334K，磁矩为2.52
We have investigated the structure, transport and magnetic properties of Ni 2 MnSb 0.5 Al 0.5 Heusler alloy. Structural analysis using x-ray diffraction and scanning electron microscopy has confirmed Ni 2 MnSb 0.5 Al 0.5 to be a natural composite of Ni 2 MnSb and Ni 2 MnAl phases, regardless of annealing conditions. This composite has a dendritic microstructure formed by the phase separation during solidification. The electronic phase separation was confirmed using x-ray near edge absorption spectroscopy, recorded at Mn and Ni K-edge and supported by ab-initio calculations of the same using multiple scattering theory. A thorough characterization of this novel composite form of Ni 2 MnSb 0.5 Al 0.5 Heusler alloy has been carried out by recording its magnetic and transport properties including electrical resistivity, thermal conductivity, and heat capacity. The composite micro-structure of this system plays a crucial role in drastically reducing its thermal conductivity value, while maintaining its metallic character. Unlike many oxide composites, the magnetic properties of the Ni 2 MnSb 0.5 Al 0.5 cannot be considered as the volume average of the characteristics of the two phases, rather it shows a long range ferromagnetic order with Curie temperature of 334 K and magnetic moment of 2.52