Abstract: A method is provided for preparing ceramic precursors from hydridosiloxane starting materials and then pyrolyzing these precursors to give rise to silicious ceramic materials. Si--H bonds present in the hydridosiloxane starting materials are catalytically activated, and the activated hydrogen atoms may then be replaced with nonhydrogen substituents. These preceramic materials are pyrolyzed in a selected atmosphere to give the desired ceramic product. Ceramic products which may be prepared by this technique include silica, silicon oxynitride, silicon carbide, metal silicates, and mullite.

Abstract: The present invention pertains to a method of preparing particles of superconducting ceramic powders, which method comprises:(a) dissolving the soluble salts of the cations in aqueous medium;(b) obtaining a solution having pH of between about 4 and 7 by optionally treating the aqueous medium with ammonia, or ammonium hydroxide;(c) atomizing the solution of step (b) onto liquid nitrogen at about -196.degree. C.;(d) removing the liquid nitrogen by evaporation;(e) removing the water by sublimation at reduced pressure;(f) heating the solid residue of step (e) at 40-60.degree. C. at reduced pressure;(g) calcining the solid residue in flowing oxygen or air at temperature of between about 200.degree. to 895.degree. C.; and(h) cooling the solid at a temperature of between about 900.degree. C. and ambient temperature in sufficient air or oxygen and recovering the superconducting powder having an average diameter of between about 0.1 and 10 microns.