磁気・光磁気記録材料への誘い

Abstract

This is to introduce physical backgrounds on magnetic and magneto-optical recording materials. Firstly, for each theme, fundamental configuration and its function is given. For magnetic recording, the single magnetic domain model, i.e., coherent rotation of magnetization is based on magnetic media and heads, which are applicable for recent items. It is presented that a high coercivity is required for the media from a viewpoint of high density magnetic recording. Special attention is put on a correlation between switching field distribution, SFD in the magnetization reversal and magnetic transition region between recorded domains, which leads to a development principle on materials of recording media. For magnetic heads with magnetic thin film, it is introduced that a decrease in local fluctuation of magnetic anisotropy due to grain size and its distribution is essential function for obtaining a high permeability at 10MHz range. For magneto-optical recording materials, an emphasis is in magnetic multilayer configuration in the recording media for realizing high access time in a disk operation which results in direct overwriting methods. Magnetic field- and light-modulation methods for overwriting are introduced. These contribution due to the film configurations is briefly described.