High-resolution optical spectroscopy ofTm3+ions inLiYF4: Crystal-field energies, hyperfine and de

Ho3+ crystal-field levels, magnetic ordering, and magnetoelastic coupling in the chain nickelate Ho2BaNiO5

“…This approach known as symmetry reduction is frequently applied to explain some peculiarities in optical spectra of RE ions. E.g., the problem of the absence of some spectral lines for Tm 3+ ion in LiYF 4 [34][35][36] was explained by the fact that in the case of higher symmetry which contains the true symmetry group as a subgroup, these transitions are forbidden. In nickelates R 2 BaNiO 5 , the true symmetry of the RE site is C 2v (see Fig.…”

Deformation splittings in the spectra of LaAlO3: Ho3+, Pr3+, Tm3+single crystals

“…In particular, a well resolved splitting of RE spectral lines caused by random lattice strains was observed in the spectra of tetragonal centers in LiYF4:Tm 3+ [1] and CaWO4:Ho 3+ [3] crystals and of cubic centers in hexafluoroelpasolite crystals doped with Sm, Er, Tm, or Yb [2]. It is of interest to observe such effect in the spectra of trigonal centers, in which non-Kramers ions also possess doubly degenerate CF levels.…”

“…The work is devoted to a high-resolution spectroscopy study of the perovskite-type single crystals of LaAlO3 doped with non-Kramers rare-earth ions of praseodymium, holmium and thulium. Doublets of a specific shape were observed in the spectra, which we attribute to the presence of random deformations in the crystals.It has been shown earlier that for dielectric crystals doped with rare-earth (RE) ions random deformations of the crystal lattice may result in a specific shape (with a narrow dip in the center) of spectral lines corresponding to transitions between crystal-field (CF) singlets (or Kramers doublets) and non-Kramers doublets [1][2][3]. In particular, a well resolved splitting of RE spectral lines caused by random lattice strains was observed in the spectra of tetragonal centers in LiYF4:Tm 3+ [1] and CaWO4:Ho 3+ [3] crystals and of cubic centers in hexafluoroelpasolite crystals doped with Sm, Er, Tm, or Yb [2].…”

“…It has been shown earlier that for dielectric crystals doped with rare-earth (RE) ions random deformations of the crystal lattice may result in a specific shape (with a narrow dip in the center) of spectral lines corresponding to transitions between crystal-field (CF) singlets (or Kramers doublets) and non-Kramers doublets [1][2][3]. In particular, a well resolved splitting of RE spectral lines caused by random lattice strains was observed in the spectra of tetragonal centers in LiYF4:Tm 3+ [1] and CaWO4:Ho 3+ [3] crystals and of cubic centers in hexafluoroelpasolite crystals doped with Sm, Er, Tm, or Yb [2].…”

“…[1][2][3] enabled to successfully model the line shapes and gave a tool for getting a quantitative estimate for the concentration of intrinsic lattice defects, by comparing experimental and calculated spectral shapes. To perform such calculations, the CF and electron-deformation interaction parameters are necessary.…”