Linear and Nonlinear Magneto-Optical Kerr Effect Studies of Nanostructures

本提案的目标是开展研究，旨在进一步了解先进纳米结构材料的磁性结构，包括磁性薄膜和多层材料，主要利用线性和非线性磁光克尔效应（MOKE和NLMOKE）检查。这项工作预计将与磁光数据记录和高密度垂直磁记录介质相关。磁光数字信息存储利用介质的克尔旋转进行数据读出。介质还必须具有适合稳定信息存储的某些磁特性，包括垂直易轴磁各向异性、方形环和高矫顽力。非线性磁光克尔效应的出现对磁光材料的研究提出了新的挑战。特别是非线性克尔角比线性角大大增强，极大地扩展了材料的选择范围。由于克尔角较大，在确定技术上有前景的材料时，可以强调确定优点数字的其他因素。MOKE测量将在一系列不同Pt厚度的Co/Pt和类似多层样品上进行，以系统的方式探测磁性结构和磁后效应的细节，并对这些结果进行建模。该研究将需要基于Preisach方法开发和应用新的和先进的纵向和垂直记录介质宏观滞后模型。MOKE测量也将在磁膜和多层的原位生长过程中进行，在一个特殊的电化学电池中，我们将设计并安装在我们的MOKE设备中。我们将利用线性MOKE来研究磁膜层的磁性随厚度的变化，并利用NLMOKE来监测磁膜与衬底界面处的磁性

9970058BennettThe goal of this proposal is to undertake research aimed at furthering the understanding of the magnetic structure of advanced nanostructural materials, including magnetic thin films and multilayers, utilizing primarily linear and non-linear magneto-optical Kerr effect (MOKE and NLMOKE) examinations. This work is expected to have relevance both to magneto-optical data recording and to high-density perpendicular magnetic recording media. Magneto-optical digital information storage uses the Kerr rotation of the medium for data readout. The medium must also have certain magnetic characteristics suitable for stable information storage including perpendicular easy axis magnetic anisotropy, a square loop, and high coercivity. The advent of the nonlinear magneto-optical Kerr effect introduces a new set of research challenges to materials suitable for magneto-optical applications. In particular, the fact that the nonlinear Kerr angle is greatly enhanced over the linear angle expands the choice of materials greatly. With a large Kerr angle, other factors in determining the figure of merit can be emphasized in identifying technologically prospective materials.MOKE measurements will be carried out on a series of Co/Pt and similar multilayer samples with different Pt thicknesses to probe the details of the magnetic structure and magnetic aftereffect in a systematic way and to model these results. The research will entail the development and application of new and advanced macroscopic hysteresis models for both longitudinal and perpendicular recording media, based on the Preisach approach.MOKE measurements will also be performed during the in situ growth of magnetic films and multilayers, in a special electrochemical cell we will design and install in our MOKE apparatus. The changes in the magnetic properties of a layer as a function of its thickness will be explored using linear MOKE, and the magnetism at the interface between the magnetic film and the substrate will be monitored with NLMOKE.***