Structure and charge transfer dynamics of uranyl ions in boron oxide and borosilicate glasses

Laser spectroscopic experiments, molecular dynamics simulation, and charge transfer-lattice interaction modeling have been conducted for studying the electronic and structural properties of the uranyl ion UO 2 2+ in boron oxide and borosilicate glasses. The charge transfer electronic and vibrational energy levels for uranyl ions in the glass matrices were obtained from laser excitation and fluorescence spectra of UO 2 2+ . A model structure for uranyl ions in the glass matrices was established using the method of molecular dynamics (MD) simulation in comparison with the results of extended x-ray absorption fine structure (EXAFS) for U 6+ ions in the glasses we studied. The formation and stabilization of uranyl clusters in glass matrices are interpreted in terms of charge transfer-lattice interactions on the basis of self-consistent charge transfer accompanied by lattice distortion. The latter is in the framework of the simultaneous action of pseudo-Jahn-Teller and pseudo-Jahn-Teller analog effects on charge transfers between oxygen and uranium ions.