Tunnel-magnetoresistance system with an amorphous detection layer

We have studied magnetic tunnel junctions using an amorphous CoFeNiSiB soft magnetic layer. At room temperature a tunnel-magnetoresistance ratio of 12% was achieved with a switching field of the amorphous layer of 12 Oe. The effect could be enhanced up to 22% by annealing. Investigations on single amorphous layers show a thermal stability up to 350 °C annealing temperature even for very thin layers. Due to the special preparation technique, an in-plane anisotropy is induced resulting from an oblique-incidence effect which presumably affects the short-range order of the amorphous phase.