Oscillations of interlayer exchange coupling and giant magnetoresistance in (111) oriented permalloy/Au multilayers

The existence or not of oscillatory interlayer exchange coupling of ferromagnetic layers via (111) oriented copper spacer layers is controversial. We present evidence from magnetic and giant magnetoresistance studies of well-defined antiferromagnetic interlayer coupling in single crystalline (111) permalloy/Au multilayers. Four oscillations in the coupling are observed as the Au spacer layer thickness is increased. The oscillation period is {}10 {} which is significantly shorter than the period of {}11.5 {} predicted in Ruderman-Kittel-Kasuya-Yosida based models.