Magnetoresistance in spin-valves with antiferromagnetic NiO/CuO/NiO trilayers

Magnetoresistance and exchange coupling in spin-valve films using antiferromagnetic NiO/CuO/NiO trilayers were investigated. The exchange coupling field H/sub ex/ and MR ratio in the NiO/sub 300 /spl Aring///CuO/sub 300 /spl Aring///NiO/sub 300 /spl Aring///NiFe/sub 50 /spl Aring///Cu/sub 20 /spl Aring///NiFe/sub 50 /spl Aring// films were almost constant values of 100 Oe and 4.5% despite of the variation of the inserted CuO thickness, however, the coercive field H/sub c/ increased from 80 Oe to 270 Oe. The apparent increase in the coercive field with the inserted thickness of CuO layer is due to the increment of interface roughness between antiferromagnetic NiO/CuO/NiO and pinned NiFe layers.