Physico-chemical characterization of highly pure nanocrystalline doped TZP

Yttria and scandia doped nanocrystalline tetragonal zirconia ceramics have been prepared from sintering of spray-pyrolysis powders. The average primar y crystallite size after sintering has been found equal to 70 nm from X-ray diffraction line broadening while aggregated particle size of 300 mn. has been characterized by scanning electron microscopy (SEM). No trace of segre gated Si has been detected in the grain boundaries using wavelength dispers ion scanning (WDS). Impedance diagrams show two well-resolved components in the 300-700 degreesC range. Small size of crystallites and existence of na noporosity give rise to a large grain boundary contribution compared to mic ro crystallized zirconia. (C) 2001 Elsevier Science Ltd. All rights reserve d.