Abstract: A process for forming a smooth, continuous coating of silicon carbide upon antalum carbide is disclosed, as are several useful manufacturers produced with the process. A tantalum carbide substrate may be formed directly upon metallic tantulum articles by disclosed means. The material formed with this process has been used to fabricate semiconducting devices including light emitting diodes and selective thermal radiators which can be operate at 1200 degrees C. The method is further useful for producing tantalum metal incandescent light filaments and corrosion resistant tantalum articles.

Abstract: A method for making cubic SiC devices comprising the steps of preparing a preform consisting of high purity Si on which a layer of cubic SiC has been deposited by CVD; transferring the preform to a furnace containing a molten bath of Si saturated with SiC at a temperature of between 1600.degree.-1800.degree. C., the saturation being insured by the use of a high purity graphite crucible for the Si; dipping the Si-SiC preform into the molten bath and allowing deposition of more cubic SiC on the SiC layer by reducing the temperature of the already formed cubic SiC layer from the preparing step in relation to the rest of the molten bath.

Abstract: A method of making very pure cubic silicon carbide, SiC, comprising the steps of: loading a first inner graphite cup of a Lely type furnace while cold with a large number of crystals of SiC that are used as substrates; sealing the first cup with a graphite lid; inserting the first cup into a second graphite cup and inserting them into the furnace; filling the area between the first cup and the second cup with SiC; heating the first cup to between 2300.degree. C. and 2700.degree. C. until an atmosphere saturated with Si, C, SiC.sub.2 and Si.sub.2 C is created; and cooling the furnace quickly to a temperature less than 1800.degree. C.

Abstract: A method of recovering intact at room temperature a layer of a first material, such as silicon carbide, produced by depositing it from the gas phase at a deposition temperature above room temperature on a substrate of a second material, such as silicon, having a different coefficient of thermal expansion than that of the first material. The substrate is separated from the layer prior to cooling, and then the separated layer is cooled to room temperature free of stresses otherwise present as a result of the different thermal expansions of the substrate and layer.

Abstract: A cubia, yttria stabilized halnia phosphor, doped with Ce.sup.3+, has been iscovered. The phosphor has a blue luminescence, peaking at about 4200 A, with a secondary peak in the 3800-4000 A region. The optimum composition is 3hfO.sub.2 :Y.sub.2 O.sub.3 :Ce.sup.3+ where the Ce.sup.3+ dopant ranges from 0.1-1.0 weight %.

Abstract: A method for chemical vapor deposition (CVD) of cubic Silicon Carbide (SiC) comprising the steps of etching silicon substrates having one mechanically polished face; depositing a thin buffer layer of cubic SiC formed by reaction between a heated Si substrate and a H.sub.2 C.sub.3 H.sub.8 gas mixture; and depositing SiC on the buffer layer at high temperature using H.sub.2 +C.sub.3 H.sub.8 +SiH.sub.4 mixture.