Thickness Effect on the Microstructure and Magnetization Reversal Behavior of FePt (001) Films by Alternate Layer Deposition

Microstructure and corresponding magnetization reversal behavior of ordered epitaxial Fe/Pt (001) multilayer films with large perpendicular magnetic anisotropy have been studied by electron-beam alternated layer deposition on Pt buffered MgO (100) substrates at 500 °C. The total film thickness of the Fe/Pt multilayers was varied in the range between 10 nm and 40 nm. Rocking curve (ω) scan and grazing incidence X-ray diffraction measurements confirmed the presence of the face centered tetragonal (fct) FePt ordered structure with (001) anisotropic orientation. The surface morphology was changed from single-domain nanogranular grains to multiple-domain continuous structure with increasing the bilayer numbers (thickness) of Fe/Pt multilayer films. According to the measurement of angular dependent coercivity shows a tendency of the rotation of reverse-domain type shift towards domain-wall motion with increasing the total thickness of Fe/Pt films. Above experimental results indicated that the surface morphology and magnetization reversal behavior of Fe/Pt (001) multilayer films could be systematically affected by only adjusting the nominal thickness at the same initial fabricating condition.