title: Structure and photoluminescent properties of green-emitting terbium-doped GdV1-x Px O4 phosphor prepared by solution combustion method.
abstract: Terbium-doped gadolinium orthovanadate (GdVO4 :Tb(3+) ), orthophosphate monohydrate (GdPO4 ·H2 O:Tb(3+) ) and orthovanadate-phosphate (GdV,PO4 :Tb(3+) ) powder phosphors were synthesized using a solution combustion method. X-Ray diffraction analysis confirmed the formation of crystalline GdVO4 , GdPO4 ·H2 O and GdV,PO4 . Scanning electron microscopy images showed that the powder was composed of an agglomeration of particles of different shapes, ranging from spherical to oval to wire-like structures. The chemical elements present were confirmed by energy dispersive spectroscopy, and the stretching mode frequencies were determined by Fourier transform infrared spectroscopy. UV-visible spectroscopy spectra showed a strong absorption band with a maximum at 200 nm assigned to the absorption of VO4 (3-) and minor excitation bands assigned to f → f transitions of Tb(3+) . Four characteristic emission peaks were observed at 491, 546, 588 and 623 nm, and are attributed to (5) D4  → (7) Fj (j = 6, 5, 4 and 3). The photoluminescent prominent green emission peak ((5) D4  → (7) F5 ) was centred at 546 nm. The structure and possible mechanism of light emission from GdV1-x Px O4 :% Tb(3+) are discussed. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Department of Physics, University of the Free State, Phuthaditjhaba, South Africa.
authors.forename: S J
authors.initials: SJ
authors.lastname: Motloung
authors.affiliation: Department of Physics, Islamic University, Gaza Strip, Palestine.
authors.forename: S K K
authors.initials: SK
authors.lastname: Shaat
authors.affiliation: Department of Physics, University of the Free State, Phuthaditjhaba, South Africa.
authors.forename: K G
authors.initials: KG
authors.lastname: Tshabalala
authors.affiliation: Department of Physics, University of the Free State, Bloemfontein, South Africa.
authors.forename: O M
authors.initials: OM
authors.lastname: Ntwaeaborwa
mesh_terms: D005682:Gadolinium / Q000737:chemistry*; D049449:Luminescence; D049408:Luminescent Agents / Q000737:chemistry*; D015394:Molecular Structure; D010710:Phosphates / Q000737:chemistry*; D012996:Solutions; D013725:Terbium / Q000737:chemistry*
chemical_list: D049408:Luminescent Agents; D010710:Phosphates; D012996:Solutions; D013725:Terbium; D005682:Gadolinium
keywords: combustion synthesis; orthovanadate phosphates; phosphors; photoluminescence