ACCURACY IN THE QUANTITATIVE PHASE-ANALYSIS OF SILICON NITRIDES

The accuracy in the quantitative phase analysis (QPB) of alpha- and be ta-silicon nitrides using the Gazzara method, the Rietveld method and the Whole-Powder-Pattern Decomposition (WPPD) method was examined. Int egrated intensities, which were obtained by a profile fitting techniqu e, and peak intensities were used for the Gazzara method. Experimental and analysis conditions were varied, and their influences on the accu racy of the QPA were examined. Model parameters in profile fittings, t he Rietveld method and the WPPD method were optimized, and the standar d settings for powder diffraction experiment were established. Under t he optimized condition the three methods for the QPA gave errors, meas ured as the deviation from weighed value, of 0.9, 0.8 and 0.4 mass% at the maximum and of 0.3, 0.4 and 0.1 mass% on the average. On the othe r hand, the Gazzara method using peak-intensities gave a less accurate result ranging up to 6.4 mass%.