Ternary silicon-rare earth nitrides and process for their preparation

Abstract

This invention provides a compound having the formula LnSi.sub.3 N.sub.5 wherein Ln is selected from the group consisting of scandium, yttrium, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. In addition, there is provided a method for making the compound Ln'Si.sub.3 N.sub.5 wherein Ln' is a radical selected from the group consisting of lanthanum, scandium, yttrium, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium, comprising the step of reacting SiO.sub.z, Ln'.sub.x O.sub.y in a nitrogen atmosphere in the presence of carbon at a temperature of from 1200.degree. C. to about 2000.degree. C. for at least 2 hrs., x being an integer equal to or greater than 2, y being an integer equal to or greater than 3, and z being an integer selected from 1 and 2, with the proviso that x and y are selected to result in a stable compound of Ln'.sub.x O.sub.y.

Dependencies are inferred from the claim text.