Enhanced giant magnetoresistance in spin-valves sandwiched between insulating NiO

Abstract

We have investigated the giant magnetoresistance of artificial structures containing metallic Co/Cu/Co and ${\mathrm{Ni}}_{80}$${\mathrm{Fe}}_{20}$/Cu/${\mathrm{Ni}}_{80}$${\mathrm{Fe}}_{20}$ spin-valves confined within insulating antiferromagnetic NiO layers. The observed enhanced magnetoresistance as compared to conventional all-metal spin-valves is interpreted with a semiclassical approach in which specular reflections at the metal/insulator barrier are included.