Doping Fezrb Alloy Film Giant Magnetoimpedance Effect

The Fe₈₈Zr₇B₅ based single layered films and sandwiched films using Ag as central layer prepared by radio frequency sputtering at different condition of fabricating were investigated. A systematic study of the influence of doping different atomic mass Nb, Ni and Cu on magnetic properties and giant magneto-impedance(GMI) effect was carried out. Following are summaries of our works: 1. The giant magneto-impedance effect in single FeZrBNb filmsThe GMI effect of as-deposited films don't vary obviously with doping Nb. When a constant magnetic field of about 70kA.m^-1 was applied along the transverse direction of the film plane during deposition process, the GMI ratios of the samples increased. The films annealed at 200°C for 30min showed good soft magnetic properties, and at the frequency of 13MHz, the maximum value of GMI effect reached 1.8% in longitudinal case. When a constant magnetic field of about 160kA.m^-1 was applied along the transverse direction of the film plane during annealing, the GMI ratio became larger: the maximum longitudinal GMI ratio was 2.5% at frequency 13MHz: Additional, the thickness of films was one of the factors that affected the GMI effect of the films. In order to know its effect, a thicker film of 10.5um in thickness was made. We found it had larger GMI ratio of 2.5% than that of the thinner film of 3.5um. 2. Magnetic properties and giant magneto-impedance effect in single FeZrBNi filmsOur experiment showed that the adequate Ni element could decrease the size of the grains, improve crystallization process and decrease the coercive force. However, the different doping content of Ni element has different influence on the GMI effect. In all our samples, the sample with the content Ni of 4at% has the highest GMI effect, it is 10% in longitudinal case and 8% in transverse case at the frequency of 13MHz, respectively.The dependence of the soft magnetic properties and GMI effect on the RF sputtering power has been studied. The film sputtered at 150W possessed excellent soft magnetic properties and a maximum value of GMI ratio, the film at 240W took second place, and the film at 350W was the worst. We thought that in the lower power, the heat during deposition process had enough time to dissipate and the atoms had enough time to diffuse. These conditions were obtained to make uniformity, even and...