Method of preparing ceramic compositions at lower sintering temperatures

Claim 1

A process of preparing a ceramic oxide of rutile which comprises: (a) combining a first ceramic oxide sol of noncrystalline TiO 2 with a second ceramic oxide sol of rutile (crystalline TiO 2 ) to form an inhomogenous sol, said first ceramic oxide being structurally dissimilar to and compositionally the same as said second ceramic oxide, said first ceramic oxide sol comprising a major portion and said second ceramic oxide sol comprising a minor portion of said inhomogenous sol, said minor portion being 0.02 to less than 5 wt. % of the single phase crystalline ceramic oxide of step (d) herein and effective to convert the major portion to crystalline TiO 2 in step (d) herein and said first sol and said second sol being effective to form an inhomogenous sol; (b) converting said inhomogenous sol under conditions effective to provide an inhomogenous gel, said effective converting conditions including room temprature to 70° C. in an open system for several minutes to several hours or in a closed system for one-half hour to several days; (c) drying said gel under conditions effective to provide a structurally diphasic xerogel, said effective drying conditions including ambient temperature for several hours to 3 days, an oven at about 110° to about 125° C. for about 30 minutes, a microwave oven for several minutes or a reducing furnace at about 200° to about 700° C. for about 10 minutes; and (d) sintering said structurally diphasic xerogel under conditions effective to provide a single phase crystalline ceramic oxide of rutile, said effective sintering conditions including a temperature in the range of 700°-1650° C.