Charge Transfer Spectra of Divalent Transition Metal Ions in LiCl and LiBr

Abstract

Optical absorption spectra of LiCl and LiBr single crystals containing Cu²⁺, Ni²⁺, Co²⁺, Fe²⁺ or Mn²⁺ have been studied in the range of 20.0 to 52.0 kcm⁻¹. Several absorption bands of medium intensity are observed and found to be temperature insensitive. These absorption bands are assigned to the electron transfer transitions from halogen ions to the central metal ions in MeX₆ complexes. Splitting of the absorption bands is observed in LiBr, which is interpreted as caused by the spin-orbit interaction in Br⁻ ions.