Open AccessOPTIMIZATION OF Tc IN EPITAXIAL GdBaCuO SUPERCONDUCTING THIN FILM BY INVERTED CYLINDRICAL SPUTTERING
Author(s) -
Yanrong Li,
Xinzhao Liu,
Jie Xu,
J. Geerk,
R. Smithy
Publication year - 1997
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.46.2023
Subject(s) - thin film , sputtering , materials science , substrate (aquarium) , epitaxy , deposition (geology) , superconductivity , analytical chemistry (journal) , optoelectronics , composite material , nanotechnology , condensed matter physics , chemistry , layer (electronics) , organic chemistry , sediment , geology , biology , paleontology , oceanography , physics
Thin films of GdBaCuO(GBCO) compound have been deposited in situ onto LaAlO3 single crystal substrates by inverted cylindrical sputtering.The variation of superconductive properties of the thin films with the substrate temperature and sputtering pressure has been systematic investigated.By the optimization of deposition parameter,high quality c-axis epitaxial GBCO thin films of Tc0>92K were reproducibly grown at the substrate temperature of 720—820℃ with a low deposition total pressure (40Pa).The Tc0 of the best sample is as high as 93.2K.Only by changing the target composition into GdBa2Cu4Oy (Gd124),was it observed that the samples always contain some a-axis oriented films,impling that excess copper would favour a-axis growth in thin films,and the Tc of the samples is lower than that with Gd123 target.The superconductivity of the thin films under high substrate temperature was clearly improved by the procedure of special post oxygenization at 400℃ in ozone atmosphere.These results are very useful to further prepare large area thin films of GBCO.