Synthesis of the Orthorhombic Phase of ZrO ₂

Abstract

Single‐phase orthorhombic ZrO 2 was prepared by quenching from high temperature and high pressure. The lattice parameters are a 0 =0.5042, b 0 =0.5092, and c 0 =0.5257 nm; the calculated density is 6.09 Mg·m −3 . This phase is metastable under atmospheric pressure and reverts to the monoclinic phase either on heating above 300°C or when it is ground in a mortar.