Spectrum of Er3+ in Single Crystals of Y2O3

Abstract

The spectrum of Er3+ in single crystals of Y2O3 has been examined from 0.225 to 2.4 μ in absorption and fluorescence, and energy levels have been assigned. The Slater integrals and spin—orbit coupling parameter have been determined, which give the best over-all agreement between the centers of gravity of the observed groups of levels and the 4f11 SLJ energy levels of the ``free'' Er3+ ion; they are F2=429.583 cm—1, F4=65.012 cm—1, F6=7.136 cm—1, ζ=—2383.17 cm—1. Of the two inequivalent cation sites, C2 and C3i, one can with consistency demonstrate that the site without inversion symmetry (C2) gives rise to the entire observed spectrum.