Study on the giant magnetoimpedance effect of FeCuCrVSiB multilayered films

Abstract

Giant magneto-impedance (GMI) effect of a multilayered film with the structure o f (FM/SiO2)3/Ag/(SiO2/FM)3 (FM≡FeCu CrVSiB) was studied. The multilayere d film was deposited by radio frequency sputtering onto a single crystal Si subs trate. A constant magnetic field of about 72kA/m was applied along the longitudi nal direction of the film plane during deposition process, and then the samples were annealed at different temperatures. Results obtained show that the multila yered film has good soft magnetic properties and GMI effect even though in the a s-deposited state. The maximum magnetoimpedance ratios are about 45% and 44% in longitudinal and transverse cases, respectively. After the samples were annealed at 230℃ for 90min, the best GMI effect could be obtained. The maximum longitud inal and transverse magnetoimpedance ratio up to 251% and 277% were obtained at the frequency of 8.5MHz, respectively. The GMI effect in this multilayered struc ture is much stronger than the one in FeCuCrVSiB/Ag/FeCuCrVSiB sandwiched film w ith the same thickness of total magnetic layers.