G. M. Safiullin

EPR and optical spectroscopy of Yb3+ ions in single crystal CsCaF3

CsCaF3 crystals doped with Yb3+ were studied using EPR and optical spectroscopy methods. Several types of paramagnetic centers of Yb3+ were found including a paramagnetic center in an uncommon 12-coordinated position. The schemes of the energy levels of the observed centers are determined and the potentials of the respective crystalline fields are calculated.

Optical spectra of octahedral cubic and trigonal Yb3+ impurity centers in KMgF3 and KZnF3 crystals

Groups of lines corresponding to octahedral cubic and trigonal impurity centers have been isolated in complex many-center luminescence and excitation spectra of Yb3+-doped KMgF3 and KZnF3 crystals. The crystal-field potentials derived from the spectra are in good agreement with those of similar centers in CsCaF3:Yb3+ crystal studied earlier.

EPR and optical spectroscopy of neodymium ions in KMgF3 and KZnF3 crystals

KMgF3 and KZnF3 crystals doped with Nd3+ ions were studied using EPR and optical spectroscopy methods. Several types of paramagnetic centers of Nd3+: KMgF3 — two of tetragonal and one of rhombic symmetry; KZnF3 — one of tetragonal and one of trigonal symmetry were found. Parameters of the corresponding spin Hamiltonians were determined. Using optical spectroscopy paramagnetic centers Nd2+ and Nd4+ in KMgF3 were found.

Crystal field of octahedral Yb3+ centers in a CsCaF3 crystal

The phenomenological crystal-field potentials of cubic and trigonal Yb3+ centers in a CsCaF3 crystal have been determined from the experimental energy-level schemes. These potentials are compared with the potentials of the analogous centers in the isomorphic hosts KMgF3 and KZnF3. Information about the phonon spectrum of a CsCaF3:Yb crystal was obtained from the electronic-vibrational structure of the luminescence spectra.