Characterization of pure and doped zirconia nanoparticles with infrared transmission spectroscopy

Infrared transmission spectroscopic studies of pure and doped zirconia nanoparticles with different average particle sizes have been made with conventional XRD and TEM techniques. Infrared spectra of these pure or doped zirconia samples are well characterized by their unique spectral features or optical phonons. Blue shifts and broadening of the absorption bands are observed with the decrease of particle size. The seeming "disappearances" of band 628 cm^-1 in pure zirconia nanoparticles and band 610 cm^-1 in the doped zirconia nanoparticles are attributed to the overlap of broad absorption bands. Blue shift of the absorption bands are also caused by the doping of Al₂O₃, which exists metastably in the Y-TZP lattice and decreases the interplanar distance. The contributions of the "interface effect" and "fine size effect" to infrared absorption are also discussed.