Microstructures and magnetic properties of [SiO₂/FePt]₅/Ag thin films

Abstract

[SiO₂/FePt]₅/Ag thin films were deposited by RF magnetron sputtering on the glass substrates and post annealing at 550 °C for 30 min in vacuum. Vibrating sample magnetometer and X-ray diffraction analyser were applied to study the magnetic properties and microstructures of the films. The results show that without Ag underlayer [SiO₂/FePt]₅ films deposited onto the glass are FCC disordered; with the addition of Ag underlayer [SiO₂/FePt]₅/Ag films are changed into L1₀ and (111) mixed texture. The variation of the SiO₂ nonmagnetic layer thickness in [SiO₂/FePt]₅/Ag films indicates that SiO₂-doping plays an important role in improving the order parameter and the perpendicular magnetic anisotropy, and reducing the grain size and intergrain interactions. By controlling SiO₂ thickness the highly perpendicular magnetic anisotropy can be obtained in the [SiO₂ (0.6 nm)/FePt (3 nm)]5/Ag (50 nm) films and highly (001)-oriented films can be obtained in the [SiO₂ (2 nm)/FePt (3 nm)]₅/Ag (50 nm) films.

Keywords

[SiO₂/FePt]₅ multilayer films / SiO₂-doping / Ag underlayer / (001) orientation