Artificial fabrication and magnetic properties of non-equilibrium ordered alloys by monatomic layr control

单原子层控制非平衡有序合金的人工制造及其磁性能

基本信息

批准号：
08455316
负责人：
TAKANASHI Koki
金额：
$ 5.63万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

项目摘要

We have compared structural and magnetic properties of the Ll_0-type FeAu ordered alloy fabricated by monatomic layr control to those of Fe (x ML) /Au (x ML) superlattices, where ML represents monatomic layr thickness. X-ray diffraction peaks corresponding to the superlattice period of x+x=2x ML have been observed definitely both for x=integers and non-integers. The X-ray diffraction patterns can be simulated by the model assuming a complete layr-by-layr growth with strucutural coherence throughout the sample, indicating the formation of coherent layred structure. The perpendicular magnetic anisotropy energy has been estimated from the in-plane and perpendicular magnetization curves. The product of the perpendicular anisotropy energy K_* and the Fe layr thickness t_<Fe>, K_*・t_<Fe>, for x=integers, decreases linearly with increasing t_<Fe> as seen in many magnetic superlattices. The interface anisotorpy energy K_s evaluated from the linear relationship increases with x for 1<less than … More or equal>x<less than or equal>3, and saturates for x<greater than or equal>4, which is explained by an extended Neel model. For x=non-integers, on the other hand, K_*・t_<Fe> vs.t_<Fe> deviates from the linear relationship, and shows oscillatory behavior with a period of 1 ML.We consider that this is a consequence associated with the reduction in K_s due to the interface roughness for x=non-integers. This study provides the first discovery of the oscillatory perpendicular anisotropy in magnetic superlattices. Furthermore, FMR measurements have indicated that the in-plane fourfold anisotropy also oscillates as a function of t_<Fe> with a period of 1.ML.In order to elucidate the origin for the oscillatory magnetic anisotropies, more precise structure analyzes including high resolution TEM,EXAFS and in situ STM are necessary. Magnetooptical measurements also indicate the oscillation of the Kerr rotation for the photon energy less than 2.5 eV.For 1<less than or equal>x<less than or equal>8, in addition, prominent structure around 3-4 eV has been observed, suggesting the formation of quantum well states of 3d electrons in Fe layrs. Less

我们已经比较了由单子飞机Layr对照与Fe（X ML） /Au（X ML）超晶格制造的LL_0型Feau的结构和磁性，其中ML代表MONOATOMIC LAINR厚度。对于X =整数和非智能器的X+X = 2X ML的超晶格周期对应于X+X = 2X ML的X射线衍射峰。 X射线衍射模式可以通过模型模拟，假设整个样品中具有结构相干性，表明形成了相干铺设结构。垂直磁各向异性能量已从面内和垂直磁曲线估计。对于X =整数而言，垂直偏见的各向异性能量k_*和fe layr厚度t_ <fe>，k_* t_ <fe>，随着许多磁性级别的晶格所示，随着T_ <fe>的增加而逐渐减小。从线性关系中评估的界面各向异性能量k_s的x <小于…多或等于> x <小于或等于> 3，x <大于或等于> 4的饱和，这是由扩展的neel模型解释的。另一方面，对于x =非智能器，k_*t_ <fe> vs.t_ <fe>偏离线性关系，并显示为1 ml的振荡行为。我们认为这是由于k_s的降低而导致的，因为k_s由于x = x = x = nonnon-Integers的界面而导致的界面。这项研究提供了磁性超晶格中振荡性垂直方向异性的首次发现。此外，FMR的测量结果表明，面内四倍各向异性也随着T_ <fe>的函数振荡，为1.ml.in的函数，以阐明振动性磁各向异性的原点，更精确的结构分析包括高分辨率结构分析，包括高分辨率TEM，EXAFS和SITU STM。磁场测量还表明，小于2.5 eV的KERR旋转的振荡。为1 <小于或等于> x <小于或等于> 8，此外，已经观察到了3-4 eV的突出结构，表明形成了Fe Layrs中3D电子的量子孔状态。较少的