用于高灵敏微磁传感器的LMO膜制备与分析

采用溶胶凝胶法制备了LaMnOx(LMO)薄膜,系统研究了不同烧结温度、纵向直流磁场后退火和生长膜层数对LMO薄膜的巨磁阻抗效应的影响。结果表明,烧结温度、膜的层数以及纵向磁场后退火处理均有效提高了LMO的巨磁阻抗比,其中纵向直流磁场后退火处理提高薄膜阻抗比效果最显著,经过10Oe、400℃恒温1h磁场后退火处理后,在频率5MHz、100Oe外磁场下其磁阻抗比达15.8%,相比未后处理样品磁阻抗比提高了一倍,其对应的磁场灵敏度为0.16%/Oe。同时,实验发现磁场后退火不仅影响薄膜的巨磁阻抗比,也会改变阻抗比极大值所对应的激励频率,这一现象目前仍在探究中。

Preparation and Analysis of LMO Films for High Sensitive Micro-Magnetic Sensors

LaMnOx(LMO)films on the substrate of Ni-W alloy were prepared by sol-gel method.The effects of the sintering temperature,longitudinal DC magnetic field post-annealing and film layers on the giant magneto-impedance(GMI)property of LMO films were studied systematically.The results show that the GMI ratio can be improved effectively by above treatment me-thods,and among which the GMI ratio of the film can be improved most obviously with longitudinal DC magnetic field post-annealing.The GMI ratio reaches about 15.8% at 5 MHz in a 100 Oe applied field after post-annealing in a 10 Oe longitudinal DC magnetic field at 400 ℃ for 1h,which is about one time higher than that of the untreated sample,and the corresponding magnetic sensitivity is about 0.16%/Oe.At the same time,it is found that the longitudinal magnetic field post-annealing affects not only the GMI ratio of LMO films,but also the corresponding stimulation frequency of the maximum for the GMI ratio,and the phenomenon is still under study at present.