Calculation of the optical absorption spectrum of ErCl3 in poly(ethylene oxide) (PEO)

The optical absorption spectrum for the rare-earth ion Er3+ in a, amorphous polymer host poly(ethylene oxide) (PEO) has been calculated. A modified Ju dd-Ofelt theory has been exploited to calculate the oscillator strengths fo r the electric-dipole transitions within the 4f(11) configuration. Such tra nsitions are allowed due to the admiring of opposite-parity states via the crystal field. Pertubation theory has been used to calculate the Stark leve l energies and the corresponding eigenstates using Racah algebra formalism. A simulated spectrum has then been constructed for this model system follo wing molecular dynamics simulation generation of a sequence of physically r epresentative environments for the rare-earth ions. These environments are then used to derive the crystal-field parameters needed to calculate spectr al intensities and Stark energies. Molecular dynamics has also been used to probe such structurally interesting features as ion pairing, crystallizati on phenomena, coordination to the rare-earth ion, and radial distribution f unctions. Distinct qualitative trends were seen in the form of the spectral peaks for the different local Er3+ environments. (C) 2000 John Wiley & Son s, Inc.