Samatham S Shanmukharao, Suresh K G
Magnetic Materials Laboratory, Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076, Maharashtra, India.
J Phys Condens Matter. 2018 May 31;30(21):215802. doi: 10.1088/1361-648X/aabc17. Epub 2018 Apr 6.
The critical magnetic properties of a non-centrosymmetric B20 cubic helimagnet FeCoSi are investigated using magnetization isotherms. It belongs to the 3D-Heisenberg universality class with short range magnetic coupling as inferred from the self-consistent critical exponents [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] in combination with exchange interaction [Formula: see text]. Itinerant magnetic nature of the compound is realized by the Rhodes-Wholfarth analysis. Field-induced weak first (para[Formula: see text]helical) to second (para[Formula: see text]field-polarized) order transition is reported to occur at low critical field due to the weak spin-orbit coupling arising from the weak Dzyaloshinksii-Moriya interactions. Our study suggests the distinct phenomenological magnetic structures for Fe-based cubic magnets (Fe Co Si and FeGe) and MnSi which cause contrasting physical properties.
利用磁化等温线研究了非中心对称B20立方螺旋磁体FeCoSi的临界磁性能。根据自洽临界指数[公式：见原文]、[公式：见原文]、[公式：见原文]和[公式：见原文]以及交换相互作用[公式：见原文]推断，它属于具有短程磁耦合的三维海森堡普适类。通过罗兹-沃尔法思分析实现了该化合物的巡游磁性本质。据报道，由于弱的Dzyaloshinksii-Moriya相互作用产生的弱自旋轨道耦合，在低临界场会发生场诱导的从弱一级（顺磁[公式：见原文]螺旋）到二级（顺磁[公式：见原文]场极化）的有序转变。我们的研究表明，铁基立方磁体（FeCoSi和FeGe）和MnSi具有不同的唯象磁结构，这导致了截然不同的物理性质。
