CHEMICAL-ENGINEERING OF CVD OF HT(C) SUPERCONDUCTORS

For CVD of HTc superconductors different sources (single or multiple s ource systems, flash evaporation, aerosol formation) are possible. Aft er a comparison of some of these systems the CVD of Y1Ba2Cu3Ox superco nductors from aerosol with an ultrasonic nebulizer is described. As pr ecursors thd complexes of Y, Ba, Cu (thd = 2.2.6.6.-tetramethyl-3.5.-h eptanedionate) are used and as solvent diglyme. Deposition experiments on flat samples and at the walls of a cylindrical hole show that the process is controlled by transport in the gas phase. The layers are co ntaminated with C. The maximum transition temperature is 79 K.