The temperature dependence of the thermal conductivity of cubic ZrO2 single crystals stabilized by yttrium oxide from 8 to 40 mol % was studied in the temperature range 50–300 K. The analysis of this dependence was carried out taking into account the phase composition, local structure features, and electrical characteristics of these single crystals.

The thermal conductivity of single-crystal solid solutions (ZrO_2)_1 – _ x  _– _ y  _– _ z (Sc_2O_3)_ x (CeO_2)_ y (Y_2O_3)_ z ( x = 0.08–0.10; y = 0.005–0.01; z = 0–0.005) was measured in the temperature range 50–300 K. Phase composition and defective structure of crystals were studied.

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The effect of heat treatment at 1000° C for 400 hours on the thermal conductivity of crystals stabilized with scandium oxide, (ZrO2)1-x(Sc2O3)x (x = 0.08–0.10), and together with scandium and yttrium oxides, (ZrO2)1-x-y(Sc2O3)x(Y2O3)y (x = 0.003−0.20; y = 0.02−0.025). For crystals of zirconium dioxide stabilized with scandium oxide, the most noticeable changes in thermal conductivity concern 9ScSZ crystals, in which changes in the phase composition occur, and a noticeable amount of rhombohedral phase appears. For 8ScSZ crystals, these changes are less noticeable and are mainly caused by the ordering of oxygen vacancies and changes in the microstructure of the samples, while for 10ScSZ crystals they are practically absent. The 10ScSZ crystals have the minimum electrical conductivity, both before and after annealing, which is determined by the highest content of scandium oxide in the solid solution. Small changes in thermal conductivity concern crystals of partially stabilized zirconia codoped with scandium and yttrium oxides. For cubic crystals 8Sc2YSZ and 10Sc2YSZ, there are practically no changes in the value of thermal conductivity, the nature of the temperature dependence of thermal conductivity, and the phase composition of crystals. The introduction of yttrium oxide into solid solutions based on zirconium dioxide along with scandium oxide makes it possible to increase the stability of its phase composition and structurally dependent thermal and electrophysical characteristics.

The effect of the co-doped Yb2O3 on the transport characteristics and stabilization of the cubic phase in solid solutions based on ZrO2−Sc2O3 has been carried out.(ZrO2)1-x-y(Sc2O3)x(Yb2O3)y solid solution crystals, where (x = 0.07-0.09; y = 0.01-0.03), were grown by directional crystallization of the melt in a cold crucible. It is shown that crystals with a cubic fluorite structure were obtained at a total concentration of stabilizing oxides Sc2O3 and Yb2O3 above 10 mol%. Crystals with a total concentration of stabilizing oxides of 10 mol%, having a pseudocubic t'' -phase structure, at a fixed concentration of Sc2O3, have the maximum conductivity. It is shown that an increase in the Yb2O3 concentration in the field of cubic solid solutions leads to a decrease in the conductivity of the crystal. Crystals (ZrO2)0.9(Sc2O3)0.09(Yb2O3)0.01 have the maximum conductivity in the entire temperature range.