Microstructural study of nanocrystalline soft magnetic thin films of Fe-C and Fe-Co-C deposited by facing targets sputtering

In the present paper, we describe the fabrication of the Fe-C and Fe-Co-C thin films by facing-targets sputtering (FTS) method at room temperature and the investigation of the relationship between microstructure and magnetic properties. Fe-C and Fe-Co-C films were fabricated by a FTS apparatus with two targets of Fe or Fe₆₅Co₃₅ with C chips at room temperature. Sputtering was performed in pure Ar and films of about 300-500 nm in thickness were deposited on fused quartz and Si substrates. Crystal structure, microstructure and magnetic properties were investigated by X-ray diffraction, transmission electron microscopy, Mossbauer spectroscopy and by a vibrating sample magnetometer. Nanocrystals with higher magnetic moment and lower carbon content were dispersed in an amorphous matrix with lower moment and higher carbon content. Carbon-doping decreased the crystallite size while soft magnetic properties with small internal stress were obtained for the films.