First-Principles Molecular Spin Dynamics Study on the Magnetic Structure of Mn-Based Alloys with Cu3Au-Type Crystal Structure
First-Principles Molecular Spin Dynamics Study on the Magnetic Structure of Mn-Based Alloys with Cu3Au-Type Crystal Structure
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Cu3Au型晶体结构锰基合金磁结构的第一性原理分子自旋动力学研究
DOI：
10.1016/j.jmmm.2015.07.011
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
and N. Kimura
中科院分区：
文献类型：
--
作者：
T. Uchida;Y. Kakehashi;and N. Kimura
采用第一性原理分子自旋动力学（MSD）方法研究了具有cu3au型晶体结构的三维阻流磁体mn3pt和mn3rh的磁性和电子结构。该理论基于第一性原理紧密结合线性松饼-锡轨道哈密顿量，结合泛函积分法和等温MSD技术，使我们能够在有限温度下自动确定流动磁体的磁性结构。采用自一致位依赖有效介质进行的MSD计算表明，在nsamel温度下，具有固定晶体结构（cu3au结构）和体积的mn3pt随着温度的升高，从三角形结构向另一种非共线相发生二阶转变。另一方面，mn3rh在nsamel温度之前没有表现出相变的迹象。我们发现Mn- eg的DOS峰是导致第二近邻Mn局域矩之间铁磁耦合的原因，在Mn 3pt的费米能量（E F）约350 K时出现，而Mn 3rh的DOS峰是随着温度略高于E F的升高而出现的。
The magnetic and electronic structures of Mn 3 Pt and Mn 3 Rh, which are three-dimensional frustrated itinerant magnets with a Cu 3 Au-type crystal structure, have been investigated by means of the first-principles Molecular Spin Dynamics (MSD) method. The theory is based on the first-principles tight-binding linear muffin-tin orbital Hamiltonian combined with the functional integral method and the isothermal MSD technique, and allows us to determine automatically the magnetic structures of itinerant magnets at finite temperatures. The MSD calculations using a self-consistent site-dependent effective medium show that below the Néel temperature Mn 3 Pt with fixed crystal structure (Cu 3 Au structure) and volume exhibits a second-order transition from a triangular structure to another noncollinear phase with increasing temperature. Mn 3 Rh, on the other hand, shows no sign of a phase transition up to the Néel temperature. We found that the Mn-Eg DOS peak, which is responsible for the ferromagnetic couplings among the second nearest-neighbor Mn local moments, develops at the Fermi energy (E F) around 350 K for Mn 3 Pt, while the peak development for Mn 3 Rh occurs with increasing temperature slightly above E F.