INTERPRETATION OF THE OPTICAL-ABSORPTION SPECTRUM OF URANIUM GERMANATE

Visible and infrared absorption spectra of U4+ in UGeO4 are described and interpreted in terms of the standard parametrization scheme- One o f the two models considered is consistent with available interpretatio ns of other uranium germanates and silicates. The second one originati ng from theoretical estimation of the crystal-field effect permits exc eptional properties of the compound under consideration, in particular , an untypical assignation of the electronic energy levels and values of the crystal-field parameters in comparison with other tetragonal ox ides.