Abstract: Improved contaminant removal from alkaline- or alkali-earth metal fluoride crystal growth material can be obtained by coprecipitating an alkaline- or alkali-earth metal fluoride with a scavenging agent during synthesis of the fluoride growth material. The coprecipitation of the alkaline- or alkali-earth metal fluoride and scavenging agent can be performed using at least one of chloride, nitrate, hydroxide and carbonate salts of the alkaline- or alkali-earth metal fluoride and scavenging agent. This provides a more intimate mixture or dispersion of the scavenging agent in solid solution or as a mechanical mixture with the alkaline- or alkali-earth metal fluoride for improved outgassing and fewer trapped impurities, leading to improved radiation hardness and bulk absorption.

Abstract: A superhard form of boron suboxide comprises at least about 95% by weight B.sub.6 O and has a KNH.sub.100 value of at least about 3800 kg/mm.sup.2. In a preferred embodiment, the boron suboxide has an average grain size of about 0.1-40 microns. A method for forming the superhard boron suboxide comprises mixing boron oxide (B.sub.2 O.sub.3) and boron powder and subjecting the mixture to a temperature of 1500.degree. C. to about 2,200.degree. C. and a pressure sufficient to produce the superhard boron suboxide. The superhard boron suboxide may be made by this method with or without a sintering aid being present in the mixture of boron and boron oxide.

Abstract: Superabrasive cutting elements, backed compacts and methods for their manufacture are disclosed wherein metal coated superabrasive particles are cemented under HPHT conditions. The superabrasives bond to the metal of the coating and the metal coatings of adjacent particles bond to each other forming a matrix. A binding aid with thermal expansion characteristics close to that of the superabrasive particle can be infiltrated through or otherwise mixed with the particles to assist in the bonding between the metal coatings and to fill in voids. Catalyst and non-catalyst binding aids can also be used. Uncoated, smaller superabrasive particles can be interstitially dispersed among the coated particles to increase the superabrasive concentration and can self bond to form a cemented/sintered structure. Tungsten is a preferred metal coating and silicon is a preferred binding/sintering aid. The superabrasive can be diamond, cubic boron nitride, boron doped diamond or crushed sintered polycrystalline aggregates.