Journal of Materials Science, Vol.32, No.20, 5419-5423, 1997
Mapping of Residual-Stresses Around an Indentation in Beta-Si3N4 Using Raman-Spectroscopy
The stress dependence of the Raman bands of silicon nitride (beta-Si3N4) have been investigated and applied to indentation experiments. Seven high-frequency bands have been found to have linear and negative stress dependencies. On the other hand, low frequency bands (namely 183, 205 and 226 cm(-1) bands) showed small positive correlations with the stress. The piezospectroscopic (PS) coefficients of all the observed Raman bands have been determined. As an application, one of the PS coefficients has been used to determine the stress distribution around a triangular indentation.
Keywords:OPTICAL FLUORESCENCE;HIGH-PRESSURE;GAS-PRESSURE;SI3N4;COMPOSITES;SAPPHIRE;ABSORPTION;ALUMINA;FIBERS;SI