title: Polarization selection rules and optical transitions in terbium activated yttrium tantalate phosphor under x-ray, vacuum-ultraviolet, and ultraviolet excitations.
abstract: The terbium-activated yttrium tantalite (YTaO(4):Tb(3+)) phosphor is of great interest due to the interesting spectroscopic properties of rare earth ions in crystals and also practical use in x-ray imaging. Using the group-theoretical approach, we analyze the selection rules for the transition between Stark components of Tb(3+) in symmetry of the actual crystal field and the polarization for the allowed transitions. The luminescence upon UV, vacuum-ultraviolet (VUV), and x-ray excitation is presented and discussed. The YTaO(4):Tb(3+) phosphors are found to be efficient VUV-excited luminescent materials that could be used not only in x-ray intensifying screens, but also in mercury-free fluorescent lamps or plasma display panels.
authors.affiliation: Department of Materials Science and Engineering, Gwangju Institute of Science and Technology, 1 Oryong-dong, Buk-gu, Gwangju 500-712, South Korea. nazarov@gist.ac.kr
authors.forename: Mihail
authors.initials: M
authors.lastname: Nazarov
authors.forename: Boris
authors.initials: B
authors.lastname: Tsukerblat
authors.forename: Clare Chisu
authors.initials: CC
authors.lastname: Byeon
authors.forename: Ivan
authors.initials: I
authors.lastname: Arellano
authors.forename: Elisabeth-Jeanne
authors.initials: EJ
authors.lastname: Popovici
authors.forename: Do Young
authors.initials: do Y
authors.lastname: Noh