MICROWAVE PROPERTIES OF DOUBLE-SIDED YBa2Cu3O7-delta THIN FILMS DEPOSITED BY METALORGANIC CHEMICAL VAPOR DEPOSITION

High-quality thin films of YBa2Cu3O7-delta have been deposited by metalorganic chemical vapor deposition on both sides of 15 mm x 15 mm < 100 > LaAlO3 substrates, without requiring the use of heat sinking compounds. Typical transport data exhibited T-c's > 87 K, transition widths < 1 degrees K and J(c)'s > 10(6) A/cm(2) (measured inductively at 77 K, 0 T). Microwave surface resistance measurements (36A GHz) at temperatures between 20 K and 100 K, made using a copper cavity end-wall-replacement technique, showed a sharp drop through the transition temperature and yielded values at 77 K that were better than a 20X improvement over copper metal when scaled to 10 GHz. Double-sided coatings have been obtained by sequentially depositing each side of the substrate. Contamination of the backside during growth of the first-side film and of the first-side film during growth of the second-side film has been avoided by coating the susceptor with gold.