Quantitative X-ray diffraction analysis of polymorphic mixes of pure zirconia

An equation describing quantitatively the amounts of tetragonal and monoclinic zirconia present in a mixture is proposed for use with X-ray diffraction intensity data. The empirical equation is based on results obtained from a set of standard mixtures. The standards were prepared by mixing commercially available monoclinic ZrO2 with tetragonal ZrO2 formed by (i) heat treatment of the precipitate formed by reacting ZrOCl2 and NH4OH, (ii) thermal decomposition and heat treatment of ZrO(NO3)2. The equation has been shown to be accurate to better than +- 4 wt% over the complete composition range. An equation originally intended to determine cubic and monoclinic ZrO2 proportions, but which has frequently been applied to tetragonal and monoclinic mixtures, has been shown to produce considerable errors when applied to analysis of the tetragonal phase. The equation has been found to require modification when applied to mixtures containing tetragonal ZrO2 formed by the heat treatment of a commercially available partially stabilized zirconia powder. (author)