金属-絶縁体ナノグラニュラー膜のTMRと省電力磁気センサGIGS^®

抄録

The structure and tunnel magneto-resistance of (Fe-Ni or Fe-Co)-(Mg-F) nano-granular thin films were investigated. The films were prepared by a tandem deposition method, using Fe-Ni or Fe-Co alloy and MgF₂ insulator targets. A granular structure was found to be consisted of Fe-Ni or Fe-Co based nano-granules surrounded by thin intergranules of Mg based fluoride which were crystallized with a MgF₂ structure. These films show tunnel-type magnetoresistance which is caused by the film structure. The GIGS^® (Granular-in-Gap-Sensor) consisting of the (Fe-Co)-(Mg-F) nano-granular thin film filled into a narrow gap of soft magnetic a-CoFeSiB thin film was prepared. GIGS^® has large electrical resistance (10kΩ-10MΩ) because of high electrical resistivity of metal-nonmetal nano-granular film. The large electric resistivity causes the reduction of the electricity consumption.