Method for making rare earth metal oxide ceramic precursor compounds and use thereof

DETAILED DESCRIPTION The following terms and words are used herein and are defined to mean the following: "preceramic liquid" is the precursor composition that has been at least partially dissolved in a solvent; "green ceramic" is a solidified state of the preceramic liquid that is ready to be burnt-out; "burn-out" is the process in which controlled oxidation is used to remove carbon containing compounds from the green ceramic and results in an ceramic structure that is ready to be sintered; "sinter" is the process in which a burnt-out ceramic is heated to high temperature to relieve internal stresses, and to strengthen and solidify the rare earth metal oxide ceramic structure; The present application is directed to a new method of making rare earth oxide ceramic articles, such as fibers, thin films, coatings and bulk objects using a precursor composition.
The precursor composition can also be used as an adhesive for the cementing together of rare earth metal oxide ceramics without the introduction of other components or elements.
Although this application is primarily focused on the use of the precursor and preceramic liquids in the field of TPV, one skilled in the art would appreciate that other uses exist where the properties of rare earth metal oxide ceramics are desired.
Such uses include, but are not limited to: electro-luminescent elements and displays, colored "heads-up" displays, laser pumping devices, photochemical reactors, and so on.
The precursor composition of the present invention is unlike prior art metal alkoxide precursors which are very moisture sensitive and rely upon an irreversible sol to gel transition to control viscosity.
In contrast, exposure of the precursor composition of the present invention to typical laboratory conditions of temperature and relative humidity does not cause reaction.
Therefore, the powdered precursor composition can be simply stored in screw cap jars until needed.
The solubility properties of the powdered precursor composition are readily varied so that preceramic liquids can be made using non-polar solvents or polar solvents