Rutherford backscattering analysis of Bi-based superconducting films

[摘要] The elemental composition, film thickness and concentration depth profiles of precursor and superconducting (Bi, Pb)-Sr-Ca-Cu-O films were studied by the Rutherford backscattering spectrometry (RBS) technique. The precursor films were deposited on MgO single-crystalline substrates with an aerosol atomized ultrasonically from an aqueous nitrate solution. Precursor films, approximately 5-5.5 mum thick: were then annealed in air at temperatures ranging from 835 to 855 degreesC for 10 h. X-Ray diffraction studies revealed mainly the presence of the 2212 phase (for the bulk, T-c is approx. 85 K). Films annealed at temperatures T-a greater than or equal to 850 degreesC were superconducting, with T-c in the range 60-71 K showing a double T-c onset at 85 K and 110 K. The RES study of the Pi depth profile of precursors showed a maximum content of Bi at a depth of approximately 1-2 mum from the film surface. After film annealing, the Pi content was found to be constant from the surface to approximately 1 mum depth, then decreasing in value towards the film-substrate interface. (C) 2000 Elsevier Science S.A. All rights reserved.

[发布日期] 2000-09-03

[效力级别]  Proceedings Paper

[关键词] superconductors;Bi-based thin films;Rutherford backscattering;spray pyrolysis