Assignment of the Raman active vibration modes of β-Si3N4 using micro-Raman scattering

The vibrational modes of the beta-Si3N4 Raman active bands appearing in the wave number region between 110 and 1100 cm(-1) were determined by the polarization and the crystallographic orientation dependence of the Raman intensities of the bands using micro-Raman spectroscopy. The laser beam was focused onto a single grain with the shape of a regular hexagon or elongated hexagon on the sintered ceramic plate. The three intense bands appearing at about 185, 208, and 230 cm(-1) were attributed to the vibrational modes of E-2g, A(g), and E-1g, respectively. The remaining peaks were also assigned to the irreducible representations. (C) 1999 American Institute of Physics. [S0021-8979(99)00610-6].