A study of nanocrystalline CeO2/PrOx optoionic thin films: temperature andoxygen vacancy dependence

The structure and optical constants of praseodymia doped ceria thin films a re reported with and without oxygen annealing. These films were prepared us ing an inorganic sol-gel route and crystallized into the cubic fluorite str ucture well below 400 degrees C, with cell constants altering as a function of dopant concentration and oxygen treatment/vacancy concentration. The fi lms were also nanocrystalline, continuous and highly transparent in the reg ion between 350-1500 nm. Optical transmission decreased with increased crys tallite size due to scattering, below 600 nm. The refractive indices of the films at 800 nm in the dispersion free region were shown to vary in direct proportion to the lattice parameter/vacancy concentration and temperature treatment, and varied between 1.77 and 2.26. It is therefore proposed that they should be suitable materials for application as transparent ion interc alation films and optoionic smart windows. (C) 1999 Elsevier Science S.A. A ll rights reserved.