MICROSTRUCTURE IMAGING OF THE YBCO THIN-FILM MGO SUBSTRATE INTERFACE - HRTEM AND FOURIER-ANALYSIS OF THE MOIRE FRINGE PATTERN

Detailed microstructural aspects of the interface between YBaCuO thin films and MgO substrate are studied by means of a Fourier analysis of Moire fringe pattern obtained from HRTEM investigations of plan view s amples. The main features of the observations are large, well oriented crystallographic domains surrounded by wide boundaries. HRTEM investi gations together with the Fourier analysis show evidence of both ortho rhombic and pseudo-tetragonal structure in the YBaCuO film. An accommo dation mechanism is suggested from the Fourier analysis of the Moire f ringe pattern. (C) 1998 Published by Elsevier Science S.A.