Mode Assignments of the Raman Spectrum of Monoclinic Zirconia by Isotopic Exchange Technique

The mode assignments of the sixteen Raman bands observed for monoclinic zirconia (ZrO2) have been made by measuring the Raman spectra of the cationic- as well as the anionic-labelled compounds, that is, 91.22Zr(16O1—x18Ox)2 (x = 0.002 to 0.760) and 93.80Zr16O2. The four Raman bands at 334, 224, 192, and 180 cm—1 were not influenced by the 16O–18O substitution but were shifted to lower wavenumbers by the 91.22Zr–93.80Zr substitution, from which they are assigned to the Zr–Zr vibrations. The three Raman bands at 380, 349, and 308 cm—1 were shifted to lower wavenumbers by the 91.22Zr–93.80Zr as well as the 16O–18O substitution, from which they are assigned to the Zr–O vibrations. The eight Raman bands at 800 to 382 cm—1 and the band at 105 cm—1 were shifted to lower wavenumbers by the 16O–18O substitution but were shifted to higher wavenumbers by the 91.22Zr–93.80Zr substitution, from which they are assigned to the O–O vibrations.