Phase formation in the ZrO2 — HfO2 — Gd2O3 and ZrO2 — HfO2 — Yb2O3 systems

The formation of phases and properties of solid solutions and Gd2Zr2O7 and Yb4Zr3O12 chemical compounds in the ZrO2 — Gd2O3 and ZrO2 — Yb2O3 systems are studied. The compounds undergo a phase transformation of the type“order — disorder” and melt incongruently. The data on the parameters of the elementary cells, the melting temperatures, and the TCLE of phases in the ZrO2 — Gd2O3 and ZrO2 — Yb2O3 systems are presented. These data are compared with similar data for phases based on HfO2. The considered solid solutions are shown to be promising for the production of high-temperature, heat-insulating ceramics for growing single crystals.