ZnO插层对超薄坡莫合金薄膜各向异性磁电阻的影响

Influence of Inserted ZnO Layer on Anisotropic Magnetoresistance of Ultra-Thin Permalloy Films

利用多靶磁控溅射系统制备了一系列坡莫合金薄膜样品Ta(4 nm)/ZnO(t)/Ni81Fe19(20 nm)/ZnO(t)/Ta(3nm),研究了ZnO插层厚度、基片温度对坡莫合金薄膜各向异性磁电阻(AMR)和微结构的影响。利用四探针法测量薄膜样品的AMR值,利用X射线衍射仪分析样品的微结构。结果表明:由于ZnO插层的"镜面反射"作用,选择适当厚度的ZnO插层能够大幅度提高坡莫合金薄膜AMR值,对于厚度为20 nm的Ni81Fe19薄膜,在基片温度为400℃时,通过插入2 nm厚的ZnO插层使得AMR值较不加插层提高了11%。

A variety of the ultra-thin permalloy films,Ta（ 4 nm） /ZnO（ t） /Ni81Fe19（ 20 nm） /ZnO（ t） /Ta（ 3 nm）,were synthesized by multi-target DC magnetron sputtering on substrates of ultra-thin Corning glass. The impacts of the deposition conditions,such as the thickness of the inserted ZnO layer,sputtering power and pressure,on the microstructures and anisotropic magneto-resistance（ AMR） were evaluated. The ultra-thin films were characterized with X-ray diffraction and 4-point probe. The results show that the thickness of the inserted ZnO layer significantly enhances the AMR,possibly because of the＂mirror reflection＂of the inserted ZnO layer. The AMR of the 20 nm thick Ni81Fe19film,grown at a substrate temperature of 400℃ with an inserted ZnO layer 2 nm in thickness,was found to be increased by 11%.