Development of amorphous thin film meander trilayers and investigation of GMI effect

Trilayer structures of 50 and 100 nm thin amorphous CoFeB layers with a central 100 and 200 nm thin Cu layer respectively were sputtered onto a thermally oxidized Si wafer. 300 μm long strips of 3-20 μm width was structured using a standard mask with various strip lines and meanders which were connected in series and were then formed by plasma etching. Magnetization curves, parallel to the easy axis and hard axis of uniaxial anisotropy, were measured by the magnetooptical Kerr effect exhibiting anisotropy fields of around 2 kA/m and low coercivity in the hard axis direction, depending on the film thickness. The MI effect was measured manually from 10 MHz to 1 GHz by means of a network analyzer using the reflected wave through the sample.