Absorption Spectrum of Nd3+ in LaBr3

Abstract

The absorption spectrum of 0.5 mole % Nd³⁺ in a LaBr₃ single crystal was obtained and most of the crystalline field Stark levels identified. The spectrum is very similar to that obtained from Nd³⁺ in LaCl₃ and, in fact, the crystalline field parameters that fit LaCl₃ to 5 cm^—1 fit LaBr₃ to 7 cm^—1. The major difference in the two spectra is a general shift of levels to the red in the LaBr₃. This is similar to the spectra of Pr³⁺ in the two crystals discussed previously [E. Y. Wong and I. Richman, J. Chem. Phys. 36, 1889 (1962)]. The explanation for this shift in both Pr³⁺ and Nd³⁺ spectra is probably the same.