Optical Absorption Spectrum and Optical Zeeman Effect in CaWO4:Yb3+

Abstract

The absorptionspectrum of 0.01%—0.05% ytterbium‐doped calcium tungstate is reported, observed at liquid‐helium temperature. Some of the samples contained sodium for charge compensation. The effect of Na charge compensation for Yb was found to be similar to previous results observed for Na‐compensated Ce in the same host. The spectrum was found to contain extensive complex structure that may be associated with the known lattice modes. The crystal‐field parameters have been calculated to fit the main lines of the spectrum, and the g values that are known. The calculation was made both with and without mixture of states of unequal J. Measurements of the Zeeman effect allow unambiguous identification of the symmetry of the lowest 2 F 5/2 level. In terms of the free‐ion JM states this level consists of a combination of M=± 5 2 and ± 3 2 functions. The g values for this state are g ‖ = 1.2±0.1 and g ⊥ = 1.5±0.1 observed at 31 kOe.