EPR and Optical Absorption Investigations of Photochromic Effect in Nearly Stoichiometric LiNbO3:Fe
EPR and optical absorption measurements have been performed on nearly stoichiometric lithium niobate single crystals with iron in traces and in 0.1% molar nominal amount. Thermal treatments in reducing atmosphere allowed to obtain samples with different Fe2+/Fe3+ ratios. The Fe2+/Fe3+ dynamic has been observed by irradiating the samples with UV and visible light in the temperature range 4-300 K: the photochromic effect resulted to be more evident in the strongly reduced crystals. A simple model to explain the photochromic behavior in nearly stoichiometric LiNbO3:Fe is proposed.
Paula Maria Vilarinho
M. C. Mozzati, A. G. Badalyan, G. Demaestri, P. Galinetto, F. Rossella, V. Bermúdez, C. B. Azzoni, G. Samoggia, "EPR and Optical Absorption Investigations of Photochromic Effect in Nearly Stoichiometric LiNbO3:Fe", Materials Science Forum, Vols. 514-516, pp. 152-155, 2006