1. Lanthanum-stabilized europium-doped cubic barium chloride: An efficient x-ray phosphor.
- Author
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Edgar, A., Zimmermann, J., von Seggern, H., and Varoy, C. R.
- Subjects
LUMINESCENCE ,CHLORINE ,PROPERTIES of matter ,SOLUTION (Chemistry) ,INTERMEDIATES (Chemistry) ,OPTICAL diffraction - Abstract
We report the photoluminescence and x-ray luminescence of lanthanum-stabilized cubic barium chloride with europium (Eu
2+ ) doping, of general composition Ba1-x-y Euy Lax Cl2+x . X-ray diffraction patterns confirm that the material adopts a cubic fluorite structure for x=0.125 and 02+ substituting for Ba 2+ giving a site of cubic symmetry, based on the excitation spectra which show a T2g band and Eg band similar to those in cubic SrCl2 :Eu. The 420 nm band has a very different lifetime and excitation spectrum and is assigned to Eu2+ ions which have an associated chlorine interstitial ion. The two bands are also found in the x-ray luminescence spectra. For both bands, and an additional minor emission at 520 nm found only at low temperatures and for high Eu concentrations, there is a common excitation in the UV from 150 to 200 nm which we attribute to excitons associated with the high concentration of chlorine interstitials. ESR measurements support a two-site model for the interpretation of the optical spectra. A measurement of the x-ray luminescence intensity compared to a standard commercial Gd2 O2 S:Tb phosphor sheet shows approximately equal brightness. [ABSTRACT FROM AUTHOR]- Published
- 2010
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