The electronic structure of Cs₂NaEuCl₆

Abstract

The visible absorption spectrum and magnetic circular dichroism (MCD) spectrum have been measured for Cs₂NaEuCl₆ at room temperature. The absorption spectrum and Zeeman splitting have been measured at liquid helium temperature as well. The Eu³⁺ is in a site of six-coordinate octahedral symmetry. Transitions from the ⁷ F ₀(A _1g ) ground state and, thermally populated ⁷ F ₁(T _1g ) state to the ⁵ D ₀(A _1g ), ⁵ D ₁(T _1g ), and ⁵ D ₂(T _2g + E_g ) states have been observed. The fourth-order crystal-field parameter (B ₄) has been found to be 10–11 cm^-1 at both temperatures. A rich vibrational structure was seen on the two electric diple-allowed transitions and an assignment of the observed vibrations made. At liquid helium temperature the g values of the ⁵ D ₁(T _1g ) and ⁵ D ₂(T _2g ) states were found to be 1·5±0·15 and 1·5±0·5, respectively.