Process for preparing superconductive thick films

摘要

A process of forming on a substrate a coating of a precursor of a crystalline rear earth alkaline earth copper oxide or heavy pnictide mixed alkaline earth copper oxide electrical conductor and converting the precursor to the crystalline electrical conductor. The coating precursor is provided by (a) preparing a solution comprised of a volatilizable solvent and, as a solute, metal-ligand compounds of each of the metals forming the crystalline electrical conductor, the proportions of the solute metals corresponding to those present in the precursor coating and the ligands being inorganic ligands chosen to be volatilizable on heating, (b) spraying the aqueous solution to form discrete liquid particles each containing the metals as metal-ligand compounds in proportions corresponding to those present in the precursor coating, (c) evaporating at least a portion of the volatilizable solvent from the liquid particles to form solid particles each containing the metals as metal-ligand compounds in proportions corresponding to those present in the precursor coating. The solid particles can be formulated as a screen printing composition to facilitate coating on the substrate.