Joseph Okil - Academia.edu (original) (raw)
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CSIC (Consejo Superior de Investigaciones Científicas-Spanish National Research Council)
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Papers by Joseph Okil
Physica B: Condensed Matter, 2016
Physica B: Condensed Matter, 2014
a b s t r a c t YBO 3 :Tb 3 þ nanocrystalline phosphors were successfully deposited by a solution... more a b s t r a c t YBO 3 :Tb 3 þ nanocrystalline phosphors were successfully deposited by a solution-combustion method, using rare-earth nitrates, urea and boric acid as starting materials. The crystal structure, morphology, chemical composition and photoluminescence properties of the films were investigated by X-ray diffraction (XRD) and atomic force microscopy (AFM). The results of SEM and XRD revealed that the powders were composed of spherical YBO 3 :Tb 3 þ nanocrystals with average grain size of between 50 and 100 nm. The electron diffraction spectroscopy (EDS) confirmed the presence of the Y, B, O, and C. The XRD measurements revealed YBO 3 :Tb 3 þ (JCPDS:83-1205) structure when annealed at 1000 1C for 2 h. The YBO 3 :Tb 3 þ powders exhibited emissions at 490, 545 and 585 nm, which were assigned to the 5D 4 -7F 6 , 5D 4 -7F 5 and 5D 4 -7F 4 transitions of Tb 3 þ , respectively. Among them, the green emission at 545 nm (5D 4 -7F 5 ) was dominant.
Physica B: Condensed Matter, 2016
Physica B: Condensed Matter, 2014
a b s t r a c t YBO 3 :Tb 3 þ nanocrystalline phosphors were successfully deposited by a solution... more a b s t r a c t YBO 3 :Tb 3 þ nanocrystalline phosphors were successfully deposited by a solution-combustion method, using rare-earth nitrates, urea and boric acid as starting materials. The crystal structure, morphology, chemical composition and photoluminescence properties of the films were investigated by X-ray diffraction (XRD) and atomic force microscopy (AFM). The results of SEM and XRD revealed that the powders were composed of spherical YBO 3 :Tb 3 þ nanocrystals with average grain size of between 50 and 100 nm. The electron diffraction spectroscopy (EDS) confirmed the presence of the Y, B, O, and C. The XRD measurements revealed YBO 3 :Tb 3 þ (JCPDS:83-1205) structure when annealed at 1000 1C for 2 h. The YBO 3 :Tb 3 þ powders exhibited emissions at 490, 545 and 585 nm, which were assigned to the 5D 4 -7F 6 , 5D 4 -7F 5 and 5D 4 -7F 4 transitions of Tb 3 þ , respectively. Among them, the green emission at 545 nm (5D 4 -7F 5 ) was dominant.