Submillimeter electron-nuclear excitation spectra in CsCdBr3:Ln3+ (Ln=Tm, Ho) crystals

Abstract
The ESR spectra of single and pair impurity centers of thulium and holmium ions in CsCdBr3:Tm3+ and CsCdBr3:Ho3+ crystals are measured in the frequency range 160-400 GHz. Analysis of the characteristic features of the hyperfine structure of the ESR lines and analysis of the variations in the spectra as a function of the temperature and external magnetic field shows that the Ln3+ ions substitute for Cd2+ ions and predominantly form symmetric pair centers of the type Ln3+-(vacancy at a neighboring Cd2+ site)-Ln3+. The ESR spectra of CsCdBr3: Ln3+ crystals are used to make a positive identification of the optical spectra of selective laser excitation.