Synthesis and crystallization of anisotropic shaped ZrO2 nanocrystalline powders by hydrothennal process

The nanocrystalline ZrO2 powders with anisotropic shapes were synthesized from the amorphous zirconium hydroxide powder (P I) and the tetragonal zirconia powder (P2) by hydrothermal process with the reaction temperature range 150-250 degreesC and additive concentration 1, 5 M NaOH solutions. With increasing the reaction temperature, the particle shape was altered from spherical to spindle- or rod-like and the fraction of monoclinic phase increased. In 5 M NaOH solution, the particle shape was actively changed and the transformation to the monoclinic was faster than in I M NaOH solution. (C) 2002 Elsevier Science B.V. All rights reserved.