Energy loss and x-ray analysis of major constituents in silicon oxynitride ceramics

Abstract

Silicon Oxynitride (Si2N2O) is an orthorhombic phase that often occurs as a minor phase In Si3N4-base structural ceramics. It is thought to form as a result of oxygen surface contamination of the constituent powder particles, usually exhibits a rod or plate morphology and may react with sintering aids or impurities in the system. The structure of Si2N2O is a network of distorted Si-centered SiN3O tetrahedra in which the tetrahedral environment of the Si is similar to its environment in Si3N4 and SiO2. The average Si-N bond length is smaller, compared to both Si3N4 allotropes, with an Si-0 bond length typical of most silicates. EELS spectra of Si3 N4, and SiO2 are well known.Here we present the first results of a high resolution EELS study to compare the energy loss core edges of Si, 0 and N in Si2N2O to the corresponding edges in Si3N4 and SiO2.