Co/GaAs(100)界面形成以及Co超薄膜磁性质的研究

利用同步辐射光电发射和铁磁共振(FMR)研究了Co/GaAs(100)界面形成以及Co超薄膜的磁性质.结果表明,在低覆盖度(约为0.2nm)下,Co吸附原子与衬底发生强烈的界面反应,在覆盖度为0.9nm时,形成稳定的界面.从衬底扩散出的Ga原子与Co覆盖层合金化,而部分As原子与Co原子发生反应,形成稳定的键合,这些反应产物都停留在界面处很窄的区域(0.3—0.4nm)内.另一部分As原子偏析在Co覆盖层表面.结合理论模型,详细地讨论了界面结构及Ga，As原子的深度分布.FMR结果表明,生长的Co超薄膜具 关键词：

STUDIES OF INTERFACE FORMATION OF Co/GaAs(100) AND THE MAGNETIC PROPERTY OF ULTRATHIN Co FILMS

Synchrotron radiation photoemission and ferromagnetic resonace(FMR) measurement have been used to study the interface formation of Co/GaAs(100) as well as the magnetic property of ultrathin Co films.The results show strong interface disruption and reaction between overlayer and substrate at low Co coverage(～0.2nm),At the coverage of 1nm,a stable interface forms.The Ga atoms in bulk GaAs may exchange with Co atoms and diffuse into Co overlayer,while a certain amount of As reacts with Co atoms,forming stable Co-As bonding.These reaction products lie in the narrow region near the interface(0.3—0.4nm).The remanent part of As will segregates on the surface of Co overlayer.Based on a theoretical model,the interface structure and concentration profile are discussed in detail.The FMR result demontrates that the ultrathin Co film consists of good-quality crystals and has a chemical homogeneity.