A RAMAN SPECTRAL CHARACTERIZATION OF CERAMICS IN THE SYSTEM ZRO2-TIO2

Ceramics of zirconium titanate, ZrTiO4, were prepared by the mixed oxide route, sintered at 1400-degrees-C and cooled at various rates: water quench to 1-degrees-C h-1. Mixed oxide-prepared ceramics of Zr5Ti7O24 Were sintered at 1400-degrees-C and cooled at 6-degrees-C h-1. TEM analysis of the ZrTiO4 ceramics showed the development of an incommensurate superstructure in the more slowly cooled specimens. The Zr5Ti7O24 ceramics exhibited a commensurate superstructure with a tripled a-axis. Raman spectra were obtained from polished ceramic specimens at room temperature. Major differences between spectra for ZrTiO4 ceramics are believed to reflect differences in the degree of cation ordering. The Raman spectrum for Zr5Ti7O24 is similar to that of slowly cooled ZrTiO4 but there are significant differences.