Lineshift and linewidth in optical spectra of europium salts

Abstract

The lineshift and the linewidth of the transition⁵ D ₀ →⁷ F ₀ has been measured in EuCl₃ · 6H₂O, Eu(NO₃) · 6H₂O and Eu₂O₃ as a function of temperature between 4.2 and 300 °K. In all cases the lines are shifted to the blue (shorter wavelength) with increasing temperature. A linear relationship is found between the lineshifts and the internal energies of the compounds.—In Eu(C₂H₅SO₄)₃ · 9H₂O the linewidth of several transitions from the⁵ D ₀ state to the crystal field states of the⁷ F _i levels have been measured at 4.2 °K. The linewidths are compared with those expected for a depopulation of the⁷ F _i states by phonons.