Effect of sputtering parameters and sample size on giant magnetoimpedance effect in NiFe and NiFe/Cu/NiFe films

NiFe single layered films and NiFe/Cu/NiFe sandwich films are fabricated by MEMS technology to investigate the influence of sputtering parameters and sample size on the giant magnetoimpedance (GMI) effect in thin films. Optimal sputtering parameters are selected based on the GMI ratio and magnetization curves of the different single layered thin films. The maximum GMI ratio of 15% is observed in NiFe/Cu/NiFe sandwich film with a length of 4 mm, the NiFe layer width of 100 μm and the Cu layer width of 40 μm. The result shows that GMI effect of thin films can be significantly improved by proper sputtering parameters, well-designed sample size and sandwich structure.