Optical spectroscopy of ${\mathrm{Yb}}_{2}{\mathrm{Ti}}_{2}{\mathrm{O}}_{7}$ and ${\mathrm{Y}}_{2}{\mathrm{Ti}}_{2}{\mathrm{O}}_{7}:{\mathrm{Yb}}^{3+}$ and crystal-field parameters in rare-earth titanate pyrochlores

Optical spectroscopy of ${Yb}_{2} {Ti}_{2} O_{7}$ and $Y_{2} {Ti}_{2} O_{7} : {Yb}^{3 +}$ and crystal-field parameters in rare-earth titanate pyrochlores

B. Z. Malkin, A. R. Zakirov, M. N. Popova, S. A. Klimin, E. P. Chukalina, E. Antic-Fidancev, Ph. Goldner, P. Aschehoug, and G. Dhalenne

Phys. Rev. B 70, 075112 – Published 27 August 2004

Abstract

Optical absorption spectra of the ${Yb}_{2} {Ti}_{2} O_{7}$ single crystals and luminescence spectra of the $Y_{2} {Ti}_{2} O_{7} : Yb$ (1%) polycrystalline samples were registered at temperatures $4.2 - 300 K$ . These spectra and earlier published data on magnetic properties of ${Yb}^{3 +}$ ions and on the temperature dependence of the electric field gradient at Yb nuclei in ${Yb}_{2} {Ti}_{2} O_{7}$ were used to analyze the crystal-field parameters in rare-earth titanates with the pyrochlore structure. The self-consistent sets of crystal-field parameters for rare-earth ions in the $16 d$ sites with the $D_{3 d}$ symmetry that describe satisfactory all known single-ion magnetic properties and low-energy excitations in $R_{2} {Ti}_{2} O_{7}$ crystals ( $R = Tb$ , Ho, Er, Tm, Yb) are presented.