Exchange coupling and magnetoresistance in nano-oxide layer built-in specular spin valves

Spin valves with nano-oxide layers (ΔR/R=16% and ΔR∼3.7 Ω/sq) are developed based on plasma and natural oxidation processes, rendering stable giant magnetoresistance (GMR) reader with ultrahigh density recording of more than 50 Gbit/in2. A simple model is used to discuss the main features of the plasma and natural oxidation process and the magnetic coupling between two subpinned layers through the oxide layers. At full-film level, large enhancement of GMR combined with a strong exchange coupling field and thermally stable magnetic performance of these nano-oxide specular layers spin valves is demonstrated.