THE INFLUENCE OF TUNGSTEN ON THE OXYGEN SUBLATTICE IN YTTRIA-STABILIZED ZIRCONIA (YSZ)

The study of electrical conductivity, Raman and IR spectra, and microh ardness of both polycrystalline and single crystalline forms of sample s has proved that the kind of incorporation of tungsten into the YSZ l attice is a function of its concentration. However, the influence of t ungsten impurity on the investigated physical properties of YSZ is rat her weak. The electrical conductivity does not change markedly its cha racter with an exception of an anomaly at 0.1-0.2 wt% WO3. The observe d decrease of the intensities of the defect-induced Raman bands can be caused by the strong electronic influence of W6+ ions on their enviro nment and by the decrease of the number of oxygen vacancies in the str ucture. The dependence of the microhardness on the temperature is step wise. The inhomogeneities observed are connected with different impuri ty phases. The microhardness is independent of the presence of tungste n above 375 degrees C, which indicates the absence of tungsten contain ing impurity phases at these temperatures.