Comparative plasma SNMS and AES measurements on ceramic powders and fibres

SNMS depth profiles of layers of 0.4–0.8 m sized Si₃N₄, BN and partly SiC-coated B₄C powder particles and of 10 m sized SiC fibres are obtained without great expenditure on time and specimen preparation. Close contact with Au foil provides for electrical conductivity. Averaged depth profiles of a great number of particles or fibres are obtained. AES serves as a comparative method; the carrier-gas heat extraction (inert gas fusion) technique is used for the semiquantification of OH signals in SNMS. Esterification of surface OH with ethanol during suspension is not detectable. Hydrolyzation or oxidation reactions having penetrated through the bulk of BN particles cause qualitatively different depth profiles than found on Si₃N₄ particles carrying a nm thin natural (hydr-)oxidic layer. The effects of preparative surface reactions like additive coating (SiC on B₄C particles), etching and oxidation (of SiC fibres) can be monitored. Quantification attempts yield standard deviations between 10 and 50%.Presented on the 15. Kollquium über Werkstoffanalytik, Vienna, May 27–29, 1991