Exchange coupling in spin-valve structures containing amorphous CoFeB

This is the authors' abstract. We don't add key points for this paper.

(Co 0.9 Fe 0.1 ) 80 B 20 /Cu/(Co 0.9 Fe 0.1 ) 80 B 20 /Ni 80 Fe 20 /Fe 50 Mn 50 spin-valve structures with a different Ni80Fe20 layer thickness were prepared by ion-beam sputtering. Varying the thickness of the Ni80Fe20 layer made it possible to control the exchange coupling between the Fe50Mn50 and amorphous CoFeB layers. When no Ni80Fe20 layer was inserted, the exchange coupling was responsible for increasing the coercivity of the a-CoFeB layers. With increasing Ni80Fe20 layer thickness, the biasing fields of the Fe50Mn50 layer increased from 0 to 125 Oe. The critical Ni80Fe20 thickness, above which the biasing effect was observed, was experimentally estimated to be 2 nm.