Accession Number : AD0773333

Title :   Vaporization Behavior of Silicon Nitride.

Descriptive Note : Final rept. 1 Jan-31 Dec 72,

Corporate Author : CINCINNATI UNIV OHIO DEPT OF MATERIALS SCIENCE AND METALLURGICAL ENGINEERING

Personal Author(s) : Yamawaki,M. ; Hoch,M.

Report Date : OCT 1973

Pagination or Media Count : 32

Abstract : The vaporization of Si3N4 was studied to determine the gaseous products and the composition of the remaining solid phase. The gas phase above Si3N4 was found to consist mainly of N2, but Si (also at mass 28) was detected. Solid Si3N4 cubes of better than 99% theoretical density were heated in a boron nitride Knudsen cell for various lengths of time. The Knudsen cell was in a temperature gradient, the top about 50C cooler than the bottom, so that the free silicon would condense on it. Following heating, the weight loss of the cubes and the silicon collected on the lid was determined, and the silicon nitride to silicon ratio in the solid phase determined. This ratio was also determined using x-ray diffraction techniques. (Modified author abstract)

Descriptors :   *Silicon nitrides, Vaporization, Phase studies, Vapor phases

Subject Categories : Physical Chemistry
      Ceramics, Refractories and Glass

Distribution Statement : APPROVED FOR PUBLIC RELEASE