STUDY OF FE - AL2O3 ION-BEAM SPUTTERED THIN-FILMS WITH VARIOUS IRON CONTENTS

Iron and Al2O3 were simultaneously ion beam sputtered on polycrystalli ne alumina substrate at room temperature. The atomic iron concentratio n was varied in the range 5-60 at.%. Thicknesses of the films (approxi mately 450 nm) and iron concentrations were controlled using Rutherfor d backscattering spectrometry (RBS). Iron charge states and phases wer e deduced from conversion electron Mossbauer spectroscopy (CEMS) and g razing-angle X-ray diffraction (GXRD) measurements. At low iron concen trations, CEMS shows that iron is mainly dispersed in Al2O3 together w ith the presence of small iron precipitates. GXRD confirms the formati on of the FeAlO3 phase and iron aggregates. Around 40 at.% of iron big ger precipitates appear, whereas for 50 at.% magnetic aggregates with different sizes are formed. For the highest concentration only magneti cally ordered metallic particles are detected.