Microstructure and Microwave Properties of Tl2Ba2CaCu2O8 Thin Films on NdGaO3

Abstract
High-quality epitaxial Tl2Ba2CaCu2O8 superconducting thin films have been grown on NdGaO3(001) by a two step process. One film, annealed at 850°C, shows interdiffusion of Ga by secondary ion mass spectroscopy, resulting in an incomplete AC susceptibility transition at 80 K. For films annealed at lower temperature, excellent crystallinity and transport properties were obtained. Ground plane substitution of the film in a 5 GHz microstrip resonator indicated worse microwave performance than similar films on LaAlO3(001) substrates. The 2.3 GHz resonator made from the film on NdGaO3 gave significantly worse quality factor (Q) values (1850) than those made on LaAlO3.