The crystal structure of tetragonal ZrO2

In the course of a high-temperature x-ray diffraction study of tetragonal ZrO/sub 2/, a number of previously unreported reflections, which are inconsistent with a body-centered lattice, hare been observed. The intensities of most of these reflections are rather low, but the strongest of these (the (102) reflection) was observed throughout the temperature range from 1200 to 1950 deg C. during heating and from 1950 to 900 deg C. during cooling, both in purified ZrO/sub 2/ as well as in specimens containing about 2% of hafnium. (R.J.S.)