不同缓冲层对Ni_(81)Fe_(19)薄膜性能影响和微结构分析

采用磁控溅射方法制备分别以Ta和NiFeCr为缓冲层的Ta(NiFeCr)/NiFe/Ta薄膜材料.对于相同厚度的NiFe薄膜,与传统材料Ta相比,用NiFeCr作缓冲层薄膜的各向异性磁电阻有显著的提高.X射线衍射结果表明,与Ta缓冲层相比NiFeCr缓冲层可以诱导更强的NiFe(111)织构.高分辨透射电子显微镜结果表明,NiFeCr缓冲层和NiFe层的晶格匹配非常好,NiFe沿着NiFeCr外延生长,以NiFeCr为缓冲层的NiFe薄膜具有良好的晶体结构.对薄膜进行热处理,以NiFeCr缓冲层为缓冲薄膜的各向异性磁电阻值在350℃以下基本保持不变,当退火温度超过350℃后,其值会明显下降.以NiFeCr缓冲层的薄膜在350℃以下退火具有良好的热稳定性.

Effect of different buffer layers on the property of Ni81Fe19 thin films and micro- structure analysis

Ta(NiFeCr)/NiFe/Ta films with Ta and NiFeCr buffer layers were prepared by magnetic sputtering.In comparison with Ta buffer layers the anisotropic magnetoresistance(AMR) values of the films with NiFeCr buffer layers increase dramatically for the same NiFe thickness.X-ray diffraction results show that the NiFeCr buffer layer promotes the formation of a stronger(111) texture in the NiFe films.High resolution transmission electron microscopy results show that the lattices of the NiFeCr buffer layer and the NiFe layer match well and the NiFe layer grows epitaxially along the direction of NiFeCr crystallites,so the films with NiFeCr buffer layers have a good crystal structure.After the films were annealed,the AMR values of the films with NiFeCr buffer layers keep constant when the temperature is below 350 ℃ and then decreases dramatically with a further increase of temperature.The films also have a good thermal stability after heat treatment at a temperature below 350 ℃.