High-resolution spectra of LiYF4:Ho3+ in a magnetic field

Abstract We report on the first high-resolution optical spectroscopy study of LiYF 4 :Ho in an external magnetic field. Peculiarities in the hyperfine structure of holmium spectral lines are discussed for the cases H || c and H⊥ c ( H  = 0.53 and 0.87 T). The spectra reveal a strong interaction between crystal-field levels, mediated by Zeeman and hyperfine terms in the Hamiltonian. A study of the magnetic-field-dependent isotope shifts in 7 Li 0.1 6 Li 0.9 YF 4 :Ho (0.1 at.%) single crystals delivers an estimate of the difference in magnetic g factors for holmium centers with all 6 Li isotopes in the nearest surrounding of Ho 3+ ( g (0) ) and the centers having one 7 Li isotope there ( g (1) ):g (1)  − g (0)  = 0.01 ± 0.005.