9360813 Eddy The preparation of epitaxial TlBaCaCuO (TBCCO) films has been demonstrated on only a small number of substrates (Lanthanum Aluminate and Strontium Titanate). The films produced have been optimized primarily for microwave performance, and a more systematic evaluation of film properties is required. This proposal outlines a program to investigate the microstructure - composition - superconducting properties relationships for the growth of high quality, epitaxial TBCCO films. In addition to this analysis, the mechanism for preparing low resistance metal contacts to TBCCCO will be explored. Transmission electron microscopy (TEM) will be used to investigate the film microstructure and metal-TBCCO interface. The goals of the program are to optimize the composition of the TBCCO deposits to produce a more homogeneous film capable of maintaining high quality superconducting properties even at the narrowest line widths (<5um), and to understand and improve the metal-superconductor contacts. It is essential for the preparation of the highest quality to control key process variables and have the ability to vary parameters for process optimization. We believe optimization. We believe optimization of composition is the most important next step for improvement of TBCCO films to meet the stringent requirements imposed by the next generation of superconducting film applications. ***