Magnetic properties of CoPt–SiNx/Ag nanocomposite films

When the thickness of Ag under layer is 25 nm, the CoPt/Ag film has maximum out-of-plane squareness (S⊥), minimum in-plane squareness (S∥), and the largest out-of-plane coercivity (Hc⊥), they are 0.95, 0.35, and 15 kOe, respectively. Different volume percent of SiNx ceramic materials were co-sputtered with Co50Pt50 films on the Ag under layer to reduce the grain size of the CoPt film. Comparing the X-ray diffraction pattern of CoPt-SiNx/Ag films without annealing with that of the films which annealed at 600 and 700 °C, it is found that the intensities of CoPt (0 0 1) and CoPt (0 0 2) superlattice lines were reduced after annealing. As the SiNx content is raised to 50 vol%, the particle size of CoPt is reduced to be about 9 nm.