ANOMALOUS BEHAVIOR IN THERMAL-PROPERTIES OF LITHIUM METAZIRCONATE (LI2ZRO3)

Anomalous behavior observed in the thermal diffusivity of lithium metazirconate (Li2ZrO3) at the temperature range from 500 to 900 K was investigated. High-temperature X-ray diffraction measurements revealed anisotropic thermal expansion of the crystal. By dilatometric measurements on polycrystalline Li2ZrO3, hysteresis in the thermal expansion and the residual expansion in thermal cycles were observed. These observations suggest that the anisotropic thermal expansion of the monoclinic Li2ZrO3 crystal may cause the generation of microcracks on heating, and thus the thermal diffusivity would decrease at medium temperatures.