Superconducting MgB2films were obtained following a two steps approach, using the multilayered structures of MgBx/Mg as precursors deposited at low substrate temperature by sputtering of an MgB2stoichiometric target, and thermal evaporation of pure Mg. Precursors were subsequently annealed in-situ in the range of 350-600°C. The films showed a zero resistance critical temperature up to 31 K. The as-obtained MgB2films were investigated by X-Ray Photoelectron Spectroscopy (XPS) and X-Ray Auger Electron Spectroscopy (XAES) using non-monochromatic Al Kα radiation (1486.6 eV) and a double-pass CMA operating in retarding mode. The electronic structure was studied by monitoring the B1s, Mg2p, O1s core-levels and the Mg KL2, 3L2, 3Auger peak structure. For comparison, the electronic structure of an MgB2superconducting sputtering target, of a precursor film and of a non-superconducting sample obtained by sputtering from the MgB2target have also been investigated. Electron spectroscopy showed that in the superconducting systems the Mg KL2, 3L2, 3Auger peak kinetic energy position is always higher by about 0.7eV with respect to the energy position of the same Auger line measured in the nonsuperconducting samples. © 2006 IOP Publishing Ltd.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)