Giant Magnetoresistanc of Dual Spin-Valves Using Antiferromagnetic α-Fe₂O₃ as a Pinning Layer

We report the large magnetoresitance (MR) ratio of a dual spin-valve structure in α-Fe 2 O 3 (50 nm)/Co/Cu/Co/Cu/Co/α-Fe 2 O 3 (50 nm) films using the insulating antiferromagnetic α-Fe 2 O 3 as a pinning layer. The MR ratio of a dual spin-valve is obtained as 27.8%, the highest value ever reported. This large MR ratio may indicate that the specular reflection of the conduction electrons occurs at the metal/insulator (Co/α-Fe 2 O 3 ) interfaces.