Characterization of FeSe thin films prepared on GaAs substrate by selenization technique

FeSe thin films were prepared on GaAs(100) substrate by the selenization of Fe films using molecular-beam epitaxy. FeSe compound thin films were obtained at a substrate temperature above 380 degrees C. From the depth profiles of Fe and Se in the selenized film measured by Auger electron spectroscopy, it was confirmed that an FeSe layer with a constant ratio of Fe/Se was formed. The measured composition ratio of Fe/Se in the film was 1/3. It was different from the composition in Fe3Se4 or Fe7Se8, which is a stable bulk FeSe compound. From the measured M-H curve, it was found that the obtained FeSe film consisted of two phases with different magnetic properties. (C) 1997 American Institute of Physics.