The annihilation of large 1/6<301> stacking faults in melt-textured samples was studied  in situ  by means of transmission electron microscopy. It was found that the annihilation process was activated by the onset of the orthorhombic-to-tetragonal transition; thus demonstrating the instability of such defects in this oxide matrix. The observations suggested that annihilation and growth were limited by surface diffusion along Y2BaCuO5/Cu3Ba2YO7 interfaces.

F.Sandiumenge, N.Vilalta, Y.Maniette, X.Obradors: Applied Physics Letters, 1997, 70[16], 2192-4