Surface layer composition of commercial silicon nitride powders from FTIR results

Abstract

In the present study the DRIFT spectra of seven commercial Si3N4 powders produced by three different processes and nitriding media were investigated. SiHx, NHx, and OH structures could be detected in the powders. The SiHx absorption band s show the presence of tetrahedral units with different atoms (O, N, Si, H) and groups (OH, NH, NH2) combinations, which bond to the same silicon atom. Clear differences in surface layer composition could be observed.