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Luminescence Properties of Redispersible Tb 3+ ‐Doped GdPO 4 Nanoparticles Prepared by an Ethylene Glycol Route
Author(s) -
Yaiphaba Ningombam,
Ningthoujam Raghumani Singh,
Singh gmaithem Rajmuhon,
Vatsa Rajesh Kumar
Publication year - 2010
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.200900968
Subject(s) - luminescence , ethylene glycol , terbium , chemistry , nanoparticle , monoclinic crystal system , doping , polyvinyl alcohol , quenching (fluorescence) , blueshift , lanthanide , analytical chemistry (journal) , ion , photochemistry , photoluminescence , crystallography , nanotechnology , materials science , crystal structure , fluorescence , organic chemistry , optoelectronics , optics , physics
Nanoparticles of Tb 3+ ‐doped GdPO 4 (Tb 3+ = 0, 2, 5, 7, 10, and 20 atom‐%) have been prepared at a relatively low temperature of 160 °C in ethylene glycol medium. The particles crystallize in a monoclinic structure with an average crystallite size of 30–50 nm. From the luminescence study of Tb 3+ ‐doped GdPO 4 , the magnetic dipole transition ( 5 D 4 → 7 F 5 ) at 545 nm (green) was found to be more prominent than the electric dipole transition ( 5 D 4 → 7 F 6 ) at 484 nm (blue). Maximum luminescence intensity and lifetime was observed for 7 atom‐% Tb 3+ . Above 7 atom‐% Tb 3+ , a decrease in luminescence was observed. This has been attributed to a concentration‐quenching effect due to the cross‐relaxation among Tb 3+ ions. The highest luminescence intensity of Tb 3+ was observed after excitation at 274 nm ( 8 S 7/2 → 6 I 11/2 of Gd 3+ ) among various excitation wavelengths (including f–f absorptions of Tb 3+ ). This is due to an efficient transfer of energy from Gd 3+ to Tb 3+ that shows GdPO 4 to be a potential host for Tb 3+ . These nanoparticles are found to be redispersible in water and ethanol and are incorporated into polyvinyl alcohol film homogeneously. This film showed bright green emission.