The role of structure in the magnetic properties of amorphous alloys
The role of structure in the magnetic properties of amorphous alloys
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DOI：
10.1016/0370-1573(78)90012-1
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发表时间：
1978-12
期刊：
影响因子：
--
通讯作者：
R. Cochrane;Rebecca Harris;M. Zuckermann
中科院分区：
文献类型：
--
作者：
R. Cochrane;Rebecca Harris;M. Zuckermann
晶体磁性材料的晶体结构和对称性决定了其磁各向异性的性质，包括易磁化轴的方向。在非晶态金属合金中，特别是那些含有非S态稀土离子的合金中，与周围环境的耦合引起局部磁各向异性（RMA），其反映了这种系统的真实的空间结构。本文是一个尝试审查的起源和后果，这些本地耦合系统缺乏长程周期order.The文件开始与非晶态金属的结构和它的相似性的致密随机堆积的硬球（DRPHS），一种模式非常适合详细的计算机模拟的描述。实验数据的目的是评估RMA对非晶态稀土合金的磁性能的影响。正文的主要重点是详细检查军事革命的各种理论模型，这些模型是在模型计算中或在与计算机生成的集群结合中引入的。磁化强度，穆斯堡尔和比热计算的分子场近似和相关的铁磁稀土贵金属和铁磁稀土过渡金属合金的数据。结果表明，这种近似在高磁场和低温下工作良好，也提供了一个很好的描述的磁滞效应。另一方面，这些合金的rexoned状态往往出现是一个自旋玻璃状的状态，不能描述的分子场方程，但可以发现在Monte Carlo模拟的基础上的RMA。最后，在无规相位近似下和通过Monte Carlo计算分析了具有RMA的系统的自旋激发。文章最后评价了数据化的进展情况，并概述了尚未解决的相关问题。
The crystal structure and symmetry of crystalline magnetic materials determine the nature of their magnetic anisotropy including the direction of the easy axis of magnetization. In amorphous metallic alloys, particularly those containing non S-state rare earth ions, the coupling to the immediate environment gives rise to a local magnetic anisotropy (RMA) which reflects the real space structure of such systems. This article is an attempt to review The origin and consequences of these local couplings in systems which lack long range periodic order.The paper begins with a description of the structure of amorphous metals and its similarity to the dense random packing of hard spheres (DRPHS), a mode ideally suited for detailed computer simulation. The experimental data are presented with a view to assessing the effects of RMA on the magnetic properties of amorphous rare earth alloys. The main emphasis of the text is a detailed examination of the various theoretical models for RMA which have been introduced either in model calculations or in conjuction with computer generated clusters. Magnetization, Mössbauer and specific heat calculations in the molecular field approximation are presented and related to data for both ferromagnetic rare earth-noble metal and ferromagnetic rare earth-transition metal alloys. It is shown that this approximation works well at high magnetic fields and low temperatures and also provides a good description of the hysteresis effects. On the other hand, the remanent state of these alloys often appears to a be a spin glass-like state which cannot be described by the molecular field equations but can be found in Monte Carlo simulations based on the RMA. Finally, the spin excitations of systems with RMA are analyzed within a random phase approximation as well as by a Monte Carlo calculation. The article concludes with an evaluation of the progress to data and an outline of related problems yet outstanding.