title: Luminescence study on Eu(3+) doped Y(2)O(3) nanoparticles: particle size, concentration and core-shell formation effects.
abstract: Nanoparticles of Eu(3+) doped Y(2)O(3) (core) and Eu(3+) doped Y(2)O(3) covered with Y(2)O(3) shell (core-shell) are prepared by urea hydrolysis for 3 h in ethylene glycol medium at a relatively low temperature of 140 °C, followed by heating at 500 and 900 °C. Particle sizes determined from x-ray diffraction and transmission electron microscopic studies are 11 and 18 nm for 500 and 900 °C heated samples respectively. Based on the luminescence studies of 500 and 900 °C heated samples, it is confirmed that there is no particle size effect on the peak positions of Eu(3+) emission, and optimum luminescence intensity is observed from the nanoparticles with a Eu(3+) concentration of 4-5 at.%. A luminescence study establishes that the Eu(3+) environment in amorphous Y (OH)(3) is different from that in crystalline Y(2)O(3). For a fixed concentration of Eu(3+) doping, there is a reduction in Eu(3+) emission intensity for core-shell nanoparticles compared to that of core nanoparticles, and this has been attributed to the concentration dilution effect. Energy transfer from the host to Eu(3+) increases with increase of crystallinity.
authors.affiliation: Department of Physics, Manipur University, Canchipur-795003, India.
authors.forename: L
authors.initials: L
authors.lastname: Robindro Singh
authors.forename: R S
authors.initials: RS
authors.lastname: Ningthoujam
authors.forename: V
authors.initials: V
authors.lastname: Sudarsan
authors.forename: Iti
authors.initials: I
authors.lastname: Srivastava
authors.forename: S
authors.initials: S
authors.lastname: Dorendrajit Singh
authors.forename: G K
authors.initials: GK
authors.lastname: Dey
authors.forename: S K
authors.initials: SK
authors.lastname: Kulshreshtha