Nanocrystalline solid solutions, Ce1-xNdxO2, with various grain sizes were synthesized by using a sol-gel method. X-ray diffraction measurements showed that the product which was obtained by sintering the fresh gel at 200C crystallized in a single fluorite structure. The grain size was about 7.2nm. The grain size of the solid solutions increased with increasing sintering temperature. The first-order Raman spectra of the solid solutions exhibited 2 peaks. A strong band F2g mode at about 470/cm was attributed to the symmetrical breathing mode of O atoms around Ce ions. A weak band at about 580/cm was attributed to the presence of O vacancies. With increasing grain size (7.2 to 65.1nm), the F2g mode shifted by about 9/cm towards higher frequencies while the half-height width decreased. The ionic conductivity of the solid solution, Ce0.8Nd0.2O2, was equal to 0.00265S/cm; with an activation energy of 0.82eV.

Transport Property and Raman Spectra of Nanocrystalline Solid Solutions, Ce0.8Nd0.2O2, with Various Particle Sizes. X.M.Lin, L.P.Li, G.S.Li, W.H.Su: Materials Chemistry and Physics, 2001, 69[1-3], 236-40