Structural Characteristics and Thermophysical Properties of Complex Ceramic Oxides in the System Dy2O3–HfO2

Abstract

The structure and thermophysical properties of materials formed in the system Dy₂O₃–HfO₂ (molar ratio 1 : 3 to 3 : 1) as a result of isothermal firing of x-ray amorphous mixed hydroxides at temperature to 1600°C are investigated. It is shown that for ratios 1 : 3 to 1 : 1 the crystallization process results in the formation of single-phase solid solutions with the structure of defective fluorite and marked nonequivalence of the parameters of the local environment of the Dy and Hf atoms. It is determined that the ceramic based on dysprosium hafnate (Dy₂O₃: HfO₂ = 1 : 1) possesses low, practically temperature independent (to 800°C), thermal conductivity about 1.4 W/(m · K).