Structural and magnetic properties of epitaxial Fe3Si/GaAs heterostructures

Abstract High-quality epitaxial Fe 3 Si films (1 0 0) were grown on the GaAs (1 0 0) surface using molecular beam epitaxy (MBE). High-resolution X-ray diffraction analysis using an X-ray energy of 12.38 keV from synchrotron radiation gave a narrow rocking curve of ∼0.014° for the Fe 3 Si (0 0 6) reflection, with a lattice mismatch between the film and GaAs of ∼0.25% in the normal direction. Square-shaped M–H loops with a typical moment of 660 emu/cm 3 at 10 K and the easy axis along [1 0 0] were obtained for films grown at a substrate temperature ( T s ) of 150 °C, and the M–H loops at low fields show fine features for films grown at a T s of 200–300 °C. A two-step growth procedure with the initial growth at 150 °C and subsequently ramping to 250 °C was applied to minimize the interfacial reactions, thus to achieve abrupt interfaces.