Raman spectra of zirconia substituted yttria solid solutions

Raman spectroscopy of zirconia substituted solid solutions in the yttria-rich side of the Y2O3-ZrO2 binary oxide system is presented. Peak deconvolution of Raman spectra reveals a broad band centered at a Raman shift of similar to 360 cm(-1) as the main distinct contribution of zirconia addition to the spectra of the non-stoichiometric phases. The new band is associated to the different oxygen sublattice near yttria or zirconia sites. The ordered lattice of vacancies of non-substituted yttria is broken by randomly introduced oxygen atoms near zirconia sites in substituted domains. The fitting reveals that the band associated to zirconia sites appears at contens of Zr cations above 3.3 at.%. Substituted samples with lower Zr content display the same bands characteristic of yttria. Further addition of zirconia leads to the paulatine increase in intensity of the new broad band. Results indicate the given zirconia content can be the solubility limit of Zr cations in the sesquioxide substituted phase and solid solution domains with different composition coexist in the studied materials with higher zirconia content. A two-phase model is used to explain the evolution of the Raman spectra.