Amorphous-like interfacial layer between a high-Tc superconducting Tl-1223 film and a Ag substrate examined by high-voltage high-resolution transmission electron microscopy

The thin amorphous-like layer, formed at the interface between a high-Tc superconducting (Tl0.5Pb0.5)(Sr0.8Ba0.2)Ca2Cu3Oy (Tl-1223) film and a Ag substrate during heating at 910 °C, has been examined by using high-voltage high-resolution transmission electron microscopy. The interfacial layer is less than 10 nm in thickness. It contacts the (001) plane of Tl-1223 and the (113) or (133) planes of Ag in most cases. Its composition is similar to that of Tl-1223, except for the inclusion of a substantial amount of Ag. Its formation proceeds by diffusion of Ag into Tl-1223, during which a structure change first occurs at the layer of CuO2 + Ca planes. The Tl(Pb)O + the Sr(Ba)O layers are then destroyed to cause the total structure to become amorphous-like. Furthermore, we have found that it is formed under an irradiation of highly energetic electrons