Effects of Ag layers on the SiO2/FePt thin films deposited by magnetron sputtering

The effects of Ag layers with different locations and thicknesses on the structural and magnetic property of SiO2/FePt multilayer films were investigated. The non-magnetic Ag layer plays an important role in inducing (001) orientation and ordering of FePt grains, as well as the SiO2-doping reducing the grain size and the magnetic exchange coupling between grains. When the 10 nm Ag layer is moved from the bottom to the top of the SiO2/FePt multilayer film, the coercivity gradually decreases; the largest difference between the out-of-plane coercivity and the in-plane one is obtained in the sample of [SiO2(2 nm)/FePt(3 nm)]3/Ag(10 nm)/[SiO2(2 nm)/FePt(3 nm)]2. Furthermore, the location of Ag layers was fixed and the thickness was changed. The XRD curves suggest that the intensity of the (001) peak becomes the strongest with the addition of 10 nm Ag layers.