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Atomic force microscopy study of bicrystal SrTiO 3 substrates and YBCO thin films
Author(s) -
Vallet C. E.,
Prouteau C. S.,
Feenstra R.,
Hamet J. F.,
Verebelyi D. T.,
Christen D. K.
Publication year - 2000
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/(sici)1096-9918(200003)29:3<221::aid-sia724>3.0.co;2-2
Subject(s) - strontium titanate , misorientation , grain boundary , materials science , crystallite , annealing (glass) , pulsed laser deposition , thin film , atomic force microscopy , superconductivity , epitaxy , condensed matter physics , crystallography , nanotechnology , composite material , microstructure , chemistry , metallurgy , physics , layer (electronics)
Single‐crystal substrates allow the epitaxial deposition of high‐ T c superconductor (HTS) films that exhibit high critical current densities ( J c ). The decrease in J c observed for films deposited on polycrystalline crystals is attributed to misorientation between adjacent grains. To understand better this phenomenon, deposition of HTS films on bicrystal substrates is used to model the effects of a single grain boundary. The surfaces of strontium titanate (001) bicrystals with tilt boundary orientations of 7°, 15° and 24° were analyzed by atomic force microscopy (AFM). Annealing conditions were found to be a key factor for obtaining atomically smooth surfaces. The grain boundary morphologies were analyzed from sections of the AFM images. Images of YBa 2 Cu 3 O 7− x (YBCO) films produced on these substrates by pulsed‐laser deposition are shown for regions that include the grain boundaries. Different morphologies of YBCO thin films are presented. Copyright © 2000 John Wiley & Sons, Ltd.