Process for making sintered glasses and ceramics

Claim 1

In a method for making a glass or ceramic article by a vapor phase oxidation process wherein vaporized glass or ceramic source compounds are oxidized while in the vapor phase to form particulate oxide soot, the oxide soot is captured as deposited soot in a collection container or on a deposition substrate, and the deposited soot is sintered by heating to form a void-free, monolithic self-supporting glass or ceramic article, the article having a composition which includes at least one modifying oxide of a metal selected from Groups IA, IB, IIA, IIB, IIIA, IIIB, IVA, IVB and the rare earth series of the Periodic Table, the improvement wherein: (a) the vaporized source compound for at least one of the constituent metal oxides of the article is a β-diketonate complex of the selected metal; (b) the β-diketonate complex of the selected metal exhibits a vapor pressure of at least 10 mm (Hg) at a temperature below 250° C.; (c) the β-diketonate complex can be vaporized at a temperature below 250° C. without significant thermal decomposition, as evidenced by thermogravimetric analysis; and (d) the vaporized β-diketonate complex can be and is oxidized in the vapor phase to produce oxide particles of the selected metal wherein the oxide particles do not exceed about 0.1 microns in diameter.