Preparation of Epitaxially Growned Multilays Composed of Ferrimagnetic Layers and Ferrodielectric Ones and Their Application for Optical Wave Guide Devices

点击翻译按钮获取中文摘要

Artificial multilayers composed of ferrimagnetic layers and ferrodielectric ones with periodic structure possesses any characteristics of each layers and moreover, some novel effects, such as momentum one at interfaces and remarkable improvement of kerr and Faraday rotation angle are also expected.This study aimed at the development of a new type sputtering apparatus for the preparation of oxide multilayers without diffusions at interface and difference of compositions between targets and each layers as well as the establishment of the process for the oxide multilayers. With respect to the development of sputtering apparatus, the purpose was perfectly achieved. Two facing target sputtering units were mounted on the chamber to prepare the oxide multilayers and therefore, periodic alternative deposition of each ultra-thin oxide layers was achieved. The films deposited from BaFe_<12>O_<19>(BaM) targets on SiO_x/Si substrates had excellent c-axis orientation. Two type of underlayers, ZnO a … More nd CoFe_2O_4(CoS), were also prepared to make c-axis orientation of BaM ferrite layer perfect and to increase the perpendicular magnetic anisotropy of it. Some multilayered films composed of BaM, CoS and ZnO layers were prepared changing each parameters such as working gas pressure, partial oxygen pressure and substrate temperature and then, their micro structure and magnetic characteristics were investigated. Consequently, it was achieved to establish excellent process in the preparation of BaM and CoS ferrite films. Although it has been difficult to prepare ultra-thin multilayers for conventional sputtering technologies because the composition difference between targets and films was easy to occur and interfaces between each layers were likely to be disordered, it was achieved by using a new type sputtering method which was developed in this study to prepare oxide multilayers composed of different crystal structures even with ultra-thin layer thickness less than 100 A^^ﾟ.From there results, it also seemed that the preparation of multilayered films composed BaM and BaTiO_3 layers was possible. Less