The Journal of Chemical Physics · 1963 · 172 citations · 6 references
Natural SciencesMaterials EngineeringMaterials ScienceCeramic MaterialsCeramicsInorganic ChemistryElectrical Properties Of CeramicsInorganic MaterialsIonic ConductivityOxide MineralogyX-ray CrystallographyX-ray DiffractionActivation EnergyDisorder-to-order TransitionElectrical Conductivity AnalysisElectrical Conductivity MeasurementsLattice Parameter AnalysisOrder-disorder Phase DiagramOrder-disorder Phase TransitionX-ray Diffraction Analysis
In the ZrO2–CaO system cubic solid solutions of the fluorite-type structure are formed between 12 and 22 mole % CaO for specimens fired at 2000°C and subsequently quenched from 1400°C. The lattice parameter increased linearly from 5.125 to 5.144 Å with increasing CaO content. Results of x-ray diffraction intensity studies favored the oxygen-ion vacancy model over the cation interstitial model for these solid solutions. As the CaO content was increased from 13 to 20 mole %, the electrical conductivity at 1000°C decreased from 5×10—2 to 6×10—3 Ω—1 cm—1 and the activation energy increased from 1.11 to 1.35 eV. Specimens heated at 1000°C for one week showed extra x-ray diffraction lines. These data coupled with accompanying changes in electrical conductivity are discussed in terms of an order—disorder transition.
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