溅射气压对Ni_(80)Fe_(20)薄膜微结构和各向异性磁电阻的影响

Effect of sputtering pressure on the microstructure and anisotropic magnet-resistance of Ni80Fe20 thin films

为改善Ni80Fe20薄膜的性能,研究不同溅射气压对薄膜微结构和各向异性磁电阻的影响。用磁控溅射方法制备Ni80Fe20薄膜,用X射线衍射和扫描电子显微镜分析其结构,用四探针方法测量其各向异性磁电阻。实验研究发现,较高的溅射气压下制备的Ni80Fe20薄膜各向异性磁电阻比较低,薄膜磁化到饱和需要的磁场也比较大。在较低的溅射气压(0.2、0.5 Pa)下制备的Ni80Fe20薄膜具有较高的各向异性磁电阻3.7%和4.2%,而且饱和磁化场低(低于1kA/m)。分析结果表明随着溅射气压的变化,Ni80Fe20薄膜的晶格常数、颗粒大小和均匀性等微结构发生变化,导致薄膜的各向异性磁电阻效应差别很大。

The effects of different sputtering pressures on the microstructure and anisotropic magnet-resistance of Ni80Fe20 films were investigated to improve the properties of Ni80Fe20 magnetic thin films. The Ni80Fe20 films were prepared by magnetron sputtering. The film structures were measured using X-ray diffraction and a scanning electron microscope. The anisotropic magnet resistance of the films was measured using the four-point method. The Ni80Fe20 films prepared at higher sputtering pressures have lower anisotropic magnet-resistance and higher saturation magnetic fields. The films prepared at pressures of 0. 2 Pa and 0. 5 Pa have 3.7% and 4.2% higher anisotropic magnet-resistance and 1 kA/m lower saturated magnetic fields. The measurement results show that the lattice constants and grain sizes and distribution on the films change with the sputtering pressures, resulting in different anisotropic magnet-resistance.