Synthesis of Magneto-optical Films with artificial Structure Using Reactive Altemating Sputtering Technique

(1)纯Bi_3Fe_5O_<12>薄膜的非外延生长纯铋铁Gamet （BIG）是一种表现出巨大法拉第效应的磁性软材料。从磁光或微波应用的角度来看，多晶BIG （p-BIG）是一种有吸引力的材料。p-BIG是一种亚稳相，只能在薄膜状态下通过气相直接外延生长到具有以下结构的基板上：p-BIG可以在500‰的温度下生长，在石英玻璃（a- sio_2）基板上分别在800和1000‰的温度下加热，形成聚晶Y_3Fe_5O_<12> (p-YIG)或Gd_3Ga_5O_<12> (p-GGG)层。这意味着YIG（或GGG）和p-BIG的溅射过程必须通过空气中的热处理来中断。我们发现，在500℃的温度下，GGG和BIG靶材料可以通过交替反应离子束溅射（ARIBS）制备聚晶（Bi, Gd）3 (Fe, Ga) 5)12 （p-BGIGG）。p-BGIGG层无磁性，性能良好。该材料的可见光透过率为12.548，且具有较大的晶格常数（12.548），是p-BIG生长的有利衬底层。我们成功地在p-BGIGG层上生长了p-BIG薄膜，即使用ARIBS方法在同一设备上连续沉积了这两层。(2)利用ARIBS技术合成诱导BIG为主要成分的复合薄膜。利用ARIBS技术，在外延生长的BIG薄膜中掺杂Co离子。采用CoO、Co Fe2O4和Co金属作为Co源，膜的特性与Co源没有明显的相关性。在633 nm和1.5 nm处，磁化强度、矫顽力、光吸收和法拉第旋转均有明显增强。在微共掺杂的薄膜中，观察到倒置的法拉第立体环。这些现象可以通过在近红外区磁性较软且透明的大晶石中嵌入磁性较硬的Co_<3-x>Fe_xO_4尖晶石微粒的复合膜结构来理解。少

(1) Non-epitaxial growth of pure Bi_3Fe_5O_<12> filmPure Bismuth Iron Gamet (BIG) is a magnetically soft material which shows giant Faraday effect. Poly- crystalline BIG (p-BIG) is an attractive material from the view points of magneto-optical or microwave application. BIG is a metastable phase which is only obtainable in a film state by direct epitaxial growth from the vapor phase onto a substratewith the structure The p-BIG can be gown at 500ﾟC the layer of polyaystalline Y_3Fe_5O_<12> (p-YIG) or Gd_3Ga_5O_<12> (p-GGG) which are crystallized on a quartz glass (a-SiO_2) substrate by heating in air at the respective temp eratures 800 and 1000ﾟC.This means the sputtering processes for YIG (or GGG) and p-BIG must be interrupted by a heat treatment in air. We found that poly cry stalline (Bi, Gd)3 (Fe, Ga) 5)12 (p-BGIGG) can be gown by alternating reactive ion beam sputtering (ARIBS) using GGG and BIG targets at 500ﾟC.The p-BGIGG layer was nonmagnetic and good. transmittance for visible l … More ight and had large lattice constant of 12.548 _, which are much favor able characteristicsas the substrate layer for p-BIG growth. We succeeded in p-BIG film growth on p-BGIGG layer, that is, those two layers were successively deposited in the same apparatus using ARIBS method.(2) Synthesis of composite film inducing BIG as the main component using ARIBS technique ionUsing ARIBS technique, Co ion was doped in epitaxially growing BIG film. As the Co source, CoO, Co Fe2O4, and Co metal were employed No remarkable dependence of the film characteristics on the Co sou rce were found. The intense onhancement of magnetization, coercivity, optical absorption at 633 nm and I.5mum, and Faraday rotation at 1.5 mum was observed. In slightly Co-doped film, inverted Faraday hy steres is loop was observed. Those phenomena can be understood considering the compositefilm structure in whic h fine partides of magnetically hard Co_<3-x>Fe_xO_4 spinel are embedded in ep itaxially gown BIG which is m agnetically soft and tranparent in near infrared region. Less