Nanogranular MgB2 thin films on SiC buffered Si substrates prepared by an in situ method

Abstract

MgB2 thin films were deposited on SiC buffered Si substrates by sequential electronbeam evaporation of a B–Mg bilayer followed by in situ annealing. Theapplication of a SiC buffer layer enables the maximum annealing temperature of830 °C to be reached. Transmission electron microscopy analysis confirms the growth of a nanogranularMgB2 film and thepresence of a Mg2Si compound at the surface of the film. The 150–200 nm thickfilms show a maximum zero resistance critical temperatureTC0 above 37 K and acritical current density JC∼106 A cm−2 at 11 K.