Combined EPR/optical investigations of light-induced charge transfers in photorefractive materials

A way to elucidate the light-induced charge transfer processes, which lead to refractive index changes in photorefractive materials, is outlined. Usin g this method, the electron paramagnetic resonance (EPR) information on the chemical identity and structure of defects, between which the transfers oc cur, is correlated to the corresponding optical absorption bands. On the ba sis of these bands alone charge transfer phenomena can then be analyzed. Th e determination of special charge transfer features is illustrated with exa mples on defects in BaTiO3. (C) 2001 Elsevier Science B.V. All rights reser ved.