Laser Raman microprobe examination in air of small-particle-sized (powders and whiskers) TiN, TiB2, TiC, WC, ZrN, and NbN revealed the formation of surface oxides, which were induced by laser heating. The rate of oxide formation varied with the particle size of the samples and the laser power density applied. The oxides produced were characterized by their Raman spectra. Thus, the Raman spectra obtained with a microprobe should always be carefully analyzed to ascertain whether oxidation or decomposition of so-called inert materials, especially in powder form, has occurred.
