Spin-Valve films using synthetic ferrimagnets for pinned layer

The magnetic behavior of spin-valve films using Co(t(1))/Ru(0.8 nm)/Co(t(2)) synthetic ferrimagnets for the pinned layer were investigated, in which the Co(t(2)) layer is exchange-biased by a CrMnPt antiferromagnetic layer. As compared with experimental results, the magnetic behavior of Co/Ru/Co/CrMnPt films could be qualitatively explained on the basis of a coherent rotation model and was roughly classified into two cases according to the thickness of t(1) and t(2). For t(1) = t(2) the magnetization of the two Co layers changed the direction only in gentle rotation mode, which resulted in very large pinning fields. For t(1) not equal t(2) the direction of the magnetization of the two Co layers rapidly reversed, maintaining an antiparallel magnetic configuration, at a relatively small applied field. The field where the rapid magnetization reversal was caused agreed with the exchange-bias field in the spin-valve film with a single Co pinned layer whose thickness was t(1) - t(2).