Spin valves with synthetic ferrimagnet and antiferromagnet free and pinned layers

Spin valve structures with both synthetic ferrimagnet F/sub a//Re/F/sub b/ free layers and synthetic antiferromagnet F/sub 1//Re/F/sub 2//AF pinned layers are demonstrated. Physical thicknesses for the free layer of /spl ap/50 /spl Aring/ can be maintained while decreasing the effective magnetic thickness (t/sub eff/) to 8-10 /spl Aring/, without significant signal loss. Inverted structures with the synthetic free layer on top present magnetoresistance (MR) values up to 7% for t/sub eff//spl sim/17 /spl Aring/. The synthetic pinned layer gives high unidirectional exchange H/sub ex/ (/spl sim/1250 Oe) and saturation fields H/sub s/ (/spl sim/3-4 KOe) with no significant change after several hours anneal at 300/spl deg/C. MR decreases linearly as the temperature increases ((1/MR(RT))x dMR(T)/dT/spl ap/-0.0017//spl deg/C).