Magnetic and microstructural properties of Cu-doped FePt-Zr/MgO multilayer films

The magnetic and microstructural properties of Zr-doped FePt/MgO and Cu-doped FePt-Zr/MgO nanocomposite films were investigated. The samples exhibited out-of-plane anisotropy after annealing for only 5 min and their grain growth was restrained by Zr doping. The Cu-doped FePt-Zr/MgO films showed an increased tendency to grow with the (001) texture on the MgO (200) layer, because of the increase in the a -lattice parameter of L 1₀ Cu-doped FePt (002), which decreased the lattice mismatch with the MgO (200) layers. The Curie temperature decreases by about 145 K owing to the effects of Cu doing. Although the addition of Cu reduces the perpendicular magnetic anisotropy and the ability to restrain the grain growth, the addition of both Zr and Cu had a complementary effect on the magnetic and microstructural properties of FePt.