β-FeSi2thin film grown on a Si(111) surface with ferromagnetic interface

Thin iron silicide films were grown by solid phase epitaxy method on Si(111) surface. Silicide structure and magnetic properties at 40 K were observed with reflection high-energy electron diffraction and surface magneto-optic Kerr effect in-situ. The bcc-Fe film was grown at 40 K and transformed to polycrystals at 670 K annealing. The SMOKE revealed ferromagnetic property of the polycrystals at 40 K. After 820 K annealing, a β-FeSi2 film was formed. This sample was ferromagnetic at 40 K. We suggest a multilayer structure including a ferromagnetic interface between the β-FeSi2 film and the Si(111) substrate