Wydział Chemii

Mirosław Karbowiak

Janusz Drożdżyński

K. M. Murdoch

Norman M. Edelstein

Stéphani Schmitt Hubert

1997

Journal of Chemical Physics

106

3067-3077

10.1063/1.473050

Naukowa

Angielski

Artykuł

Single crystals of U³⁺ diluted into a matrix of RbY₂Cl₇ have been grown by the Bridgman–Stockbarger method. There are two different intrinsic U³⁺ sites in this crystalline host, each with an approximate C_2v site symmetry. A third minor U³⁺ site was also found. Absorption, fluorescence, and excitation spectra of these crystals were obtained at 300 and 4.2 K. Transitions belonging to each U³⁺ site were distinguished by time-gated site-selective spectroscopy. The energy levels of the two intrinsic sites were assigned and fitted to a semiempirical Hamiltonian representing the combined atomic and crystal-field interactions for a 5f³ ion at a C_2v symmetry site. Quite different ⁴F_9/2 fluorescence lifetimes were measured for the three sites, due to a multiphonon decay mechanism which is affected by differences in their respective crystal-field strengths. These results are analyzed quantitatively using the theory for the electron–phonon interaction.

https://doi.org/10.1063/1.473050

https://www.aip.org/