School of Materials Science and Engineering & Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology, Nanjing, 210094, China.
Sci Rep. 2018 Jan 8;8(1):19. doi: 10.1038/s41598-017-18240-x.
Magnetostructural coupling in MnMX (M = Co or Ni, X = Si or Ge) system attracts considerable attention for the accompanied multi-magnetoresponsive effects. However, due to the large stress generated from the structural transformation, the alloys become shattered or powder-like, hindering the further investigation and their applications. The possible solution is to embed the MnMX powders into metal matrix. In this paper, we choose MnFeNiFeSiGe as a representative of MnMX alloy and produce MnFeNiFeSiGe/Sn composite bulk by hot pressing. The magnetostructural-coupled composites exhibit an improved rate of the transformation temperature shift by magnetic field and broadened operating temperature range. Additionally, we also propose a simple formula based on the entropy-temperature diagram to calculate the isothermal entropy change, which is consistent with the results obtained by the Maxwell relation.
锰基 MX（M=Co 或 Ni，X=Si 或 Ge）体系的磁结构耦合因其伴随的多磁响应效应而引起了相当大的关注。然而，由于结构转变产生的大应力，合金变得易碎或呈粉末状，这阻碍了进一步的研究和应用。可能的解决方案是将 MnMX 粉末嵌入金属基质中。在本文中，我们选择 MnFeNiFeSiGe 作为 MnMX 合金的代表，并通过热压法制备 MnFeNiFeSiGe/Sn 复合材料块体。磁结构耦合复合材料表现出改善的磁场下相变温度漂移率和更宽的工作温度范围。此外，我们还基于熵-温度图提出了一个简单的公式来计算等温熵变，该公式与麦克斯韦关系得到的结果一致。
