Searching for the dopant ion in Eu 2+-activated BaMgAl 10O 17 phosphor with synchrotron diffraction

Abstract

Searching for the multiple sites predicted in the literature for the europium activator in the BaMgAl 10O 17:Eu 2+ phosphor, we undertook a detailed structural study using synchrotron powder diffraction. Three different positions were found for Eu 2+ in the Beevers–Ross site, near the mid-oxygen position and in substitution for the interblocks Al–O–Al bridge. By favoring the migration of the activator ion, the resulting vacancies in the Beevers–Ross sites may be a major cause of the degradation of the phosphor.