Investigation of magnetoimpedance effect in amorphous thin-film microstructures

Abstract

The objective of this research is to correlate the magnetic properties of CoFeB trilayer thin films with the impedance responses and to investigate the potential use of this material for magnetoimpedance (MI) sensor applications. Two layers of 50-nm-thin amorphous CoFeB layers with a central 100-nm copper layer were sputtered onto a thermally oxidized Si wafer. Strips and meanders of 4–20-μm width were structured by plasma etching. The MI effect of the 50∕100∕50-nm trilayer was improved after field annealing, exhibiting a maximum of up to 9% in a 20-μm-wide meander.