Absorption spectrum of BkCl3

Abstract

The absorption spectrum of thin films of BkCl3 was measured in the region ∞ 3800–48 000 cm−1 at 298°, 77°, and 4°K. The absence of transitions from the ground state to excited J=0 and J=1 states, together with the number of crystal field components observed in several isolated groups, suggested that the ground level BkCl3 is characterized by the crystal quantum number μ=0, as is the case in LaCl3:Tb3+. Assignments were made based in part on a predicted energy level scheme which assumed a systematic variation in energy level parameters over the actinide series. The free-ion electrostatic, spin orbit, and configuration interaction parameters for Bk3+ were calculated by a least squares fitting process involving 23 level assignments.