Investigation of crystal structure and associated electronic structure of Sr{sub 6}BP{sub 5}O{sub 20}

Journal Article · Sat Apr 15 00:00:00 EDT 2006 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2005.12.033· OSTI ID:20784945

Ehrenberg, Helmut ^[1]; Laubach, Sonja ^[2]; Schmidt, P C ^[2]; McSweeney, R ^[3]; Knapp, M ^[1]; Mishra, K C ^[4]

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1. Materials Science, Darmstadt University of Technology, Petersenstr. 23, 64287 Darmstadt (Germany)
2. Eduard-Zintl-Institut fuer Anorganische und Physikalische Chemie, Technische Universitaet Darmstadt, Petersenstr. 20, 64287 Darmstadt (Germany)
3. Precision Materials and Components, OSRAM SYLVANIA, Hawes Street, Towanda, PA 18848 (United States)
4. Central Research, OSRAM SYLVANIA, Beverly, MA 01915 (United States)

Strontium borophosphate phosphate (Sr{sub 6}BP{sub 5}O{sub 20}, SrBP), activated by divalent europium ions is a bluish-green phosphor emitting in a broad band with the emission peak near 480nm. In this paper, we report the crystal structure of SrBP determined from an analysis of the X-ray diffraction pattern of a prismatic single crystal (size 60{mu}mx50{mu}mx40{mu}m). This crystal was chosen from undoped phosphor powder samples prepared for this purpose by solid-state reaction. SrBP is observed to crystallize in a body-centered tetragonal lattice with the lattice parameters a=9.7895(7)A and c=19.032(3)A, the associated space group being I4-bar c2 (space group 120). Using the structural data from this study, we have also calculated its electronic structure using the augmented spherical wave method and the local density approximation (LDA). We show the ordering of the electronic states by the density of states (DOS) and the partial DOS plots. The LDA gives a direct optical band gap at the {gamma} point of about 5eV. The significance of the crystal structure and associated electronic structure is discussed with respect to maintenance of this phosphor in Hg-discharge lamps.

• OSTI ID: 20784945
• Journal Information: Journal of Solid State Chemistry, Vol. 179, Issue 4; Other Information: DOI: 10.1016/j.jssc.2005.12.033; PII: S0022-4596(05)00611-0; Copyright (c) 2005 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
BORON PHOSPHATES
DENSITY
ELECTRONIC STRUCTURE
EUROPIUM IONS
LATTICE PARAMETERS
MONOCRYSTALS
SPACE GROUPS
STRONTIUM COMPOUNDS
TETRAGONAL LATTICES
X-RAY DIFFRACTION