Effect of Cu intermediate layer thickness on microstructure and magnetic properties of fcc-FePt/ L 1 0 -FePt exchange-coupled composite films

The fcc-FePt/Cu/ L 1 0 -FePt exchange-coupled composite films with different Cu intermediate layer thicknesses were prepared on (100)-oriented single-crystal MgO substrates using DC magnetron sputtering, and the effect of Cu intermediate layer thickness on microstructure and magnetic properties of films were investigated. High (001) orientation and low coercivity field were obtained in the fcc-FePt/Cu/ L 1 0 -FePt composite films. With increasing Cu intermediate layer thickness, the chemical order parameter and coercivity of the fcc-FePt/Cu/ L 1 0 -FePt film decrease gradually. For the film with 4 nm Cu intermediate layer, annealing at an appropriate temperature could promote the interdiffusion between Cu intermediate and bottom/top FePt layers and strengthen the exchange-coupled interaction of the composite films.