Torque magnetometry study of the spin reorientation transition and temperature-dependent magnetocrystalline anisotropy in NdCo5.
Torque magnetometry study of the spin reorientation transition and temperature-dependent magnetocrystalline anisotropy in NdCo5.
复制标题
NdCo5 中自旋重定向转变和温度依赖性磁晶各向异性的扭矩磁力测量研究。
DOI：
10.1088/1361-648x/ab7ad6
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Kumar S
中科院分区：
文献类型：
--
作者：
Kumar S
我们提出了扭矩磁力测量和磁化率测量的结果，以详细研究永磁体 NdCo 5 中的自旋重定向转变 (SRT) 和磁各向异性。我们进一步展示了使用基于密度泛函理论和有限温度下磁性无序局部矩图的第一性原理计算进行的测量模拟。理论和实验数据之间的良好一致性导致了对支持 SRT 的物理原理的详细描述。特别是，我们能够解析 Nd 和 Co 亚晶格的磁化强度，并揭示 Nd 和 Co 亚晶格之间的倾斜。在易方向附近的 ac 和 ab 平面上进行的扭矩测量使我们能够估计各向异性常数 K 1、K 2 和 K 4 及其温度依赖性。通过改变晶体 ac 平面中恒定磁场的方向记录的扭矩曲线 τ (γ) 显示，随着 SRT 上温度的变化 (240< T< 285 K)，极性会发生反转。在此域内，τ (γ) 表现出与跃迁上方和下方观察到的不同寻常的特征。使用光学浮区技术生长NdCo 5 单晶。
We present the results of torque magnetometry and magnetic susceptibility measurements to study in detail the spin reorientation transition (SRT) and magnetic anisotropy in the permanent magnet NdCo 5. We further show simulations of the measurements using first-principles calculations based on density-functional theory and the disordered local moment picture of magnetism at finite temperatures. The good agreement between theory and experimental data leads to a detailed description of the physics underpinning the SRT. In particular we are able to resolve the magnetization of, and to reveal a canting between, the Nd and Co sublattices. The torque measurements carried out in the ac and ab planes near the easy direction allow us to estimate the anisotropy constants, K 1, K 2 and K 4 and their temperature dependences. Torque curves, τ (γ) recorded by varying the direction of a constant magnetic field in the crystallographic ac plane show a reversal in the polarity as the temperature is changed across the SRT (240< T< 285 K). Within this domain, τ (γ) exhibits unusual features different to those observed above and below the transition. The single crystals of NdCo 5 were grown using the optical floating zone technique.