分子束外延及溅射法制备Co/Cu多层膜结构与磁电阻的比较研究

对用分子束外延（MBE）和溅射方法制备的Co/Cu多层膜样品分别进行了结构及磁性研究．X射线分析表明两者均有良好的调制周期性，并且前者形成外延单晶结构，铁磁共振研究表明了面内六次各向异性对称的存在，说明此超晶格具有完整的面内二维结构．磁电阻测量发现，溅射制备的多层膜具有较高的磁电阻值并明显地随Cu层厚度而振荡，相应的室温磁电阻峰值分别为27%，24%，14%；而MBE制备的超晶格的磁电阻较小，其第二峰的数值只有7%．MBE超晶格界面处可能具有超顺磁性，对磁电阻和磁化强度的不同的外场依赖关系有一定的影响． 关键词：

COMPARATIVE STUDY OF STRUCTURAL AND MAGNETIC PROPERTIES OF Co/Cu MULTILAYERS MADE BY MBE AND SPUTTERING

The structural and magnetic properties of Co/Cu multilayers prepared by molecular beam epitaxy(MBE) and sputtering were investigated and compared with each other.It was found that the well defined layered structures existed in both samples,and the former was epitaxial single crystalline;while the latter was textured polycrystalline.Ferromagnetic resonance study showed the existence of a six-fold symmetry in the film plane,revealing the perfect in-plane structure of MBE samples.Giant magnetoresistance and its oscillation with the Cu thickness were found in sputtered samples.On the contrary,the magnetic resonance of MBE samples is smaller,about 7% for the second peak position.It is assumed that the superparamagnetic structure may be formed at interfaces in MBE samples which results in the different magnetic-field-dependent behaviors of magnetoresistance and- magnetization.