Mössbauer effect and X-ray diffraction investigation of Si–Fe thin films

Abstract

An X-ray diffraction and ⁵⁷Fe Mössbauer spectroscopy investigation of Si_{100– x} Fe _x (0 < x < 80) thin films prepared by combinatorial sputtering methods is reported. Resulting Mössbauer spectra were fit to Voigt-based distributions of quadrupole doublets for paramagnetic spectral components and Zeeman split sextets for ferromagnetic spectral components. In conjunction with the X-ray measurements, these results show that the Si-rich films are a mixture of dilute Fe in amorphous Si and an approximately equiatomic amorphous SiFe phase. Fe-rich films show the presence of a ferromagnetically ordered phase. For x < 73, this ferromagnetic phase is amorphous or nanostructured and for x ≥ 73, the phase is shown to be a crystalline bcc phase. Results are discussed in terms of short-range structural ordering in these alloys.

Acknowledgements

This work was supported by the Natural Sciences and Engineering Research Council of Canada, the NSERC/3M Canada Company Industrial Research Chair program in Materials for Advanced Batteries and the Killam Trusts. The authors also acknowledge the support of the Canada Foundation for Innovation, the Atlantic Innovation Fund, and other partners that fund the Facilities for Materials Characterization, managed by the Institute for Research in Materials. MDF acknowledges NSERC and the I. W. Killam and W. C. Sumner Foundations for scholarship support.