Spin valves with synthetic ferrimagnet and antiferromagnet free and pinned layers

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