This Small Business Innovation Research Phase I project involves research in the area of synthesis and processing of advanced superconducting ceramic materials. The principal objective of the proposed work is to optimize the stoichiometry, phase composition, morphology, and other characteristics of high-temperature superconducting ceramic (HTSC) powders used to produce high-quality single crystals having high critical current densities necessary for flux-trapping applications. An important additional objective is to contribute to the development of an improved understanding of certain crystal growth process parameters thought to be of prime importance in controlling growth rates and single crystal properties. The work will be concentrated on YBa2Cu3O7 (123) materials known to have useful superconducting properties and which have already been successfully fabricated as single crystals, both in the United States and in Japan. The powders will be produced using a proven combustion spray pyrolysis (CSP) method capable of providing high-purity, ultra-fine, stoichiometric powders with consistent reproducibility. Y2BaCuO5 (211) powders used in the growth of 123 single crystals, as well as 123/211 composite compositions, will also be produced. The recognized role of small additions of platinum to the crystal growth process will be explored by examining appropriate means for introducing the metal into the precursor powders. Required modifications to the CSP process required to produce preferable precursor powders will be established. Selected powders will be used in subsequent single crystal growth experiments (modified Czochralski growth method) to be conducted at Princeton University. Single crystal growth technology will be transferred from Princeton University to SSC, Inc. for continuing development and eventual commercialization as progress warrants.
