Microstructure and Microwave Properties of Tl2Ba2CaCu2O8 Thin Films on CaNdAlO4(001)

Abstract
High-quality epitaxial Tl2Ba2CaCu2O8 superconducting thin films have been grown on CaNdAlO4 (001) substrates by a two step process. Analysis results from secondary ion mass spectroscopy and X-ray energy dispersive spectroscopy of a film annealed at 850°C indicated non-uniform Nd and Ca interdiffusion from the substrate into the film. A second film, annealed at 800°C, exhibited better superconducting properties with a T c of 100.7 K, transition width of 2.5 K, and J c of 3.5×105 A/cm2 at 77 K. Microwave measurement at 77 K of a 2.3 GHz microstrip resonator made from the 800°C annealed film on a CaNdAlO4 substrate exhibited a low power Q of 2,100.