Epitaxial growth of and silicide formation in Fe/FeSi multilayers

The structural properties of multilayers consisting of Fe layers separated by Si or FeSi layers grown with molecular beam epitaxy on MgO(001) and Si(lll) are reported. Rutherford backscattering and ion channeling are used to determine the crystallinity of the layers. We find evidence for epitaxy, alloying effects, and structural coherence. Conversion electron Mossbauer spectroscopy is utilized to investigate the silicide formation in the spacer layer of Fe/FeSi multilayers and at the interface of Fe/Si layers. The silicide formed in Fe/FeSi multilayers is characterized by a broad single line Mossbauer resonance which is characteristic for the metastable CsCl-FeSi phase. For Fe/Si multilayers the Mossbauer results indicate that FeSi compounds with clearly other hyperfine parameters than the CsCl phase are formed in the spacer. (C) 1997 American Institute of Physics.