Local structure determination of Mn²⁺ in CaCl ₂:Mn²⁺ by optical spectroscopy

Excitation and emission spectra of Mn²⁺ ions in calcium chloride have been studied using the photoluminescence technique. From a crystal-field analysis of the excitation spectrum is inferred that the Mn²⁺ ion occupies the Ca²⁺ cation site forming octahedral MnCl64- complexes. A ligand inward relaxation around the Mn²⁺ is noticed as a consequence of smaller ionic radius of Mn²⁺ than that of host cation. This investigation supports the usefulness of crystal-field spectra for obtaining information on the local structure of impurity ions in ionic lattices.