具有纳米氧化层自旋阀薄膜的XPS研究  

X-ray photoelectron spectroscopy study of spin valves with specularly reflective oxide layers

作　　者：蔡永香[1,2] 王海成[1] 于广华[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]北京新材料发展中心,北京100080

出　　处：《北京科技大学学报》2008年第12期1406-1409,共4页Journal of University of Science and Technology Beijing

基　　金：国家自然科学基金资助项目(No.50671008)

摘　　要：采用X射线光电子能谱(XPS)研究了带有两种纳米氧化层(NOL)Ta/Ni80Fe20/Ir19Mn81/Co90Fe10∥NOL1∥Co90Fe10/Cu/Co90Fe10∥NOL2/Ta的镜面反射自旋阀薄膜的化学结构.研究结果表明:CoFe/NOL1和NOL2/Ta界面处发生了热力学有利的化学反应.CoFe磁性敏感层仍保持金属特性,部分氧化的CoFe和Ta发生界面反应,使得Ta覆盖层被氧化成Ta2O5,形成NOL2.由于仍存在部分金属CoFe,NOL1为不连续的氧化层,使得与IrMn层仍存在直接的交换耦合作用.在退火过程中,IrMn层中的Mn原子扩散到NOL1中;然而,由于NOL1和扩散的Mn原子发生界面反应,生成Mn的氧化物,从而阻止Mn原子的进一步扩散,使其偏聚在NOL1中.Chemical structures of the specular spin valve with two nano-oxide layers （Ta/Ni80Fe20/Ir19Mn81/Co90Fe10//NOL1// Co90Fe10/Cu/Co90Fe10//NOL2/Ta） were studied by X-ray photoelectron spectroscopy （XPS） and peak decomposition technique. The results show that there are thermodynamically favorable reactions at the CoFe/NOL1 and NOL2/Ta interfaces. The CoFe sense layer remains metallic, and the Ta capping layer near the CoFe sense layer is oxidized to Ta2O5 acting as the NOL2, which is formed through the interface reaction between the oxidized CoFe and the Ta layer. ROLl is a discontinuous oxidation layer because of the existence of some residual metallic CoFe, which allows the direct exchange coupling to exist. Mn atoms of the IrMn layer diffuse into NOL1 during annealing. However, it＇s further diffusion can be inhibited due to the formation of Mn oxides by the reaction between ROLl and the Mn diffused from IrMn during annealing.

关 键 词：纳米氧化层 X射线光电子能谱 自旋阀 交换耦合 

分 类 号：TB383[一般工业技术—材料科学与工程] TM271[电气工程—电工理论与新技术]