Agnieszka Mech

Optical spectroscopy and crystal-field analysis of U3+ : Ba2YCl7

High resolution absorption spectra of a U3+(0.3%) : Ba2YCl7 single crystal were recorded in the 4000–50 000 cm−1 range at 7 K. The observed crystal-field levels were assigned and fit to the parameters of the simplified angular overlap model (AOM) as well as a semi-empirical Hamiltonian representing the combined atomic and one-electron crystal-field interactions. The starting values of the AOM parameters were obtained from ab intio calculations. The analysis of the spectra allowed the assignment of 65 crystal-field levels with a relatively small rms deviation of 25 cm−1 and has shown that the AOM approach can predict quite well the Bkq crystal-field parameters. The value determined for the crystal-field strength parameter, Nv corresponds well with those determined for U3+ in other chloride single crystals.