INITIAL-STAGES OF INAS DEPOSITION ON SRF2-COATED EUBA2CU3O7-Y THIN-FILM SUPERCONDUCTORS

Initial stages of InAs deposition on EuBa2Cu3O7-y (EBCO) thin-film sup erconductors with a SrF2 interlayer are investigated by using synchrot ron-radiation photoelectron spectroscopy. Core-level and valence-band spectra can give information on both oxidation of InAs and reduction o f the underlying EBCO with a very thin surface layer. These spectral e volutions demonstrate that SrF2 does not affect the underlying EBCO, a nd that the two-step growth procedure, comprising the initial InAs lay er growth at room temperature and the top InAs layer growth at 200-deg rees-C, is effective in suppressing the interfacial redox reactions. F urthermore, cross-sectional transmission electron microscopy and x-ray -diffraction studies confirm that SrF2 forms a uniform layer on the EB CO surface, and that the two-step growth process can crystallize an In As top layer, which is highly (111) oriented with a full width at half -maximum of 0.25-degrees.