Author:
Gonzalez R. J.,Ritter A. L.
Abstract
Small titania particles, prepared by hydrolysis and condensation using in situ steric stabilization, have been studied by high-energy, transmission, electron energy-loss spectroscopy. Electron diffraction patterns and energy-loss spectra as a function of momentum transfer were measured for as-prepared particles (amorphous titania), particles annealed at 600 °C (primarily anatase), and particles annealed at 1000 °C (primarily rutile). The energy-loss spectra at low momentum disagreed with the loss function calculated from optical data (rutile) and disagreed with theory (rutile and anatase). The data was fit by an Elliot-like model for a resonant exciton interacting with a continuum of levels. The translational effective mass of the exciton derived from the fitting was quite large, indicating that it was self-trapped.
Publisher
Springer Science and Business Media LLC
Subject
Mechanical Engineering,Mechanics of Materials,Condensed Matter Physics,General Materials Science