SYNTHESES OF MONOCLINIC AND TETRAGONAL ZrO2 AT HIGH TEMPERATURES

Single crystals of ZrO2 in tetragonal crystal forms were synthesized by flux methods. The tetragonal crystal was transformed into a single or twinned monoclinic phase during cooling. The observed orientational relations between the two phases is ct//cm, and {100}m//{100}t. Three kinds of orientational relations were observed on heating transformation; ct is parallel to cm, bm, and am*. The equilibrium temperature of the monoclinic and the tetragonal phases is 1, 145±10°C.