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arXiv 1902.06396cond-mat.mtrl-sci
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没有一级磁跃迁,一个奇特的Mn3InC例子

Absence of first order magnetic transition, a curious case of Mn3InC

E. T. Dias, A. Das, A. Hoser, S. Emura, A. K. Nigam, K. R. Priolkar

摘要:

Mn $_3$ GaC和Mn $_3$ SnC中的体积膨胀磁结构转变已被确定是由于Mn $_6$ C八面体的畸变。尽管与Mn $_3$ SnC具有相似的晶格体积,并且与Mn $_3$ GaC中的价电子对态密度的贡献相似,但Mn $_3$ InC不像Ga和Sn反钙钛矿对应物那样经历一阶磁结构转变。利用X射线衍射、磁化强度、中子衍射和扩展X射线吸收精细结构(EXAFS)等探针对其结构和磁性进行了系统的研究,结果表明,虽然八面体畸变导致了Mn原子上的长短键和不同的磁矩,但它们之间的相互作用仍然是铁磁性的。这归因于由于与Sn和Ga相比In原子的相对较大尺寸而产生的Mn $_6$ C八面体上的应变。In原子的大小限制了Mn $_6$ C八面体的变形,从而产生仅有利于化合物中的铁磁相互作用的Mn-Mn距离。

英文摘要:

The volume expanding magnetostructural transition in Mn$_3$GaC and Mn$_3$SnC has been identified to be due to distortion of Mn$_6$C octahedra. Despite a similar lattice volume as Mn$_3$SnC and similar valence electron contribution to the density of states as in Mn$_3$GaC, Mn$_3$InC does not undergo a first order magnetostructural transformation like the Ga and Sn antiperovskite counterparts. A systematic investigation of its structure and magnetic properties using probes like x-ray diffraction, magnetization measurements, neutron diffraction and extended x-ray absorption fine structure (EXAFS) reveal that though the octahedra are distorted resulting in long and short Mn -- Mn bonds and different magnetic moments on Mn atoms, the interaction between them remains ferromagnetic. This has been attributed to the strain on the Mn$_6$C octahedra produced due to the relatively larger size of In atom compared to Sn and Ga. The size of In atom constricts the deformation of Mn$_6$C octahedra giving rise to Mn -- Mn distances that favor only ferromagnetic interactions in the compound.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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