Transmission electron microscopy of Tl-1223 films on lanthanum aluminate

The microstructure of (Tl, Pb)-1223 films on (1 0 0)LaAlO3 single-crystalline substrate was investigated on cross-sections of the specimens by conventional transmission electron microscopy in combination with selected area electron diffraction and by high resolution transmission electron microscopy. The (Tl, Pb)-1223 films showed the presence of the planar defects such as stacking faults and twins on the [1 0 0] planes. The numerous planar defects are accompanied by visible dislocations. Sporadically CaO grains were identified as secondary phase in the (Tl, Pb)-1223 film by energy dispersive X-ray diffraction point analysis and by X-ray mapping. The adhesion of the Tl-1223 film to the substrate was excellent.