POLARIZED ABSORPTION-SPECTRA AND ENERGY-LEVELS FOR U3+(5F3) IN LACL3

Polarized absorption spectra covering the wavelength range 5600 to 25 000 Å are reported for U3+(5f 3) doped into single crystal LaCl3. Spectra were recorded at liquid helium, liquid nitrogen, and at room temperatures. Temperature-dependent polarized spectra help establish many crystalline electric-field (CEF) split J levels not directly excited from the ground state due to selection rules for C3h symmetry. Analysis of the data confirms the earlier (1959) assignments made by S. P. Cook at The Johns Hopkins University to the ground state manifold Stark levels. For 4I9/2, the ground state manifold, we find: μ (±5/2) =0, μ (±1/2) =210, μ (±3/2) =241, μ (±5/2) =440, and μ (±3/2) =458 all in energy units of cm−1. Uncertainty in establishing these levels is within several wave numbers and involves over 150 temperature-dependent transitions. © 1979, American Institute of Physics. All rights reserved.