Accession Number:

AD0656599

Title:

INFLUENCE OF CHARGE COMPENSATION ON UV-EXCITATION OF RARE-EARTH FLUORESCENCE

Descriptive Note:

Corporate Author:

HARRY DIAMOND LABS ADELPHI MD

Personal Author(s):

Report Date:

1967-05-01

Pagination or Media Count:

26.0

Abstract:

Excitation spectra for the fluorescence transitions of Tb3, Eu3 , and Dy3 were obtained at room temperature on single crystals of the tungstates and molybdates of Ca, Sr, Pb, and Cd, having the Scheelite structure, and on terbium-doped crystals of CaF2 and SrF2. Rare-earth concentrations were nominally one atomic percent and charge compensation was provided by vacancy formation or interstitials, by substitution in cation-sites or by anionic substitutions. Strong UV-excitation bands were found for Tb- and Eu-doped crystals and weaker bands for Dy-doped matrices. The bands generally occur near the host-lattice absorption-edge but their intensities and energy positions are strongly influenced by the charge-compensating defects near the active ion. The long wavelength peaks of the bands occur at energies coinciding with 4f-level positions of the rare-earth ions, suggesting a strong perturbation of 4f-levels by charge transfer states. The short-wavelength regions of the excitation bands are ascribed to exchange transfer from UV-absorbing groups.

Subject Categories:

  • Lasers and Masers
  • Atomic and Molecular Physics and Spectroscopy
  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE