title: Optimization of photoluminescence of Y(2)O(3):Eu and Gd(2)O(3):Eu phosphors synthesized by thermolysis of 2,4-pentanedione complexes.
abstract: Spherical shaped nanoparticles of series Y(2 - x)Eu(x)O(3) (x = 0.06, 0.10, 0.20, and 2) and Gd(2 - x)Eu(x)O(3) (x = 0.06, 0.10) were prepared by thermolysis of 2,4-pentanedione complexes of Y, Gd, and Eu. The bixbyite phase of Gd(2 - x)Eu(x)O(3) samples was formed at 500 degrees C, whereas the thermal decomposition of Y and Eu complexes' mixtures occurred at higher temperatures. Linearity in the concentration dependence on lattice parameter confirmed the formation of solid solutions. The distribution of Eu(3+) in Gd(2 - x)Eu(x)O(3) was changed with thermal annealing: in the as-prepared sample (x = 0.10) the distribution was preferential at C(3i) sites while in the annealed samples, Eu(3+) were distributed at both C(2) and C(3i) sites. Rietveld refinement of site occupancies as well as emission spectra showed a random distribution of cations in Y(2 - x)Eu(x)O(3). The photoluminescence (PL) measurements of the sample showed red emission with the main peak at 614 nm ((5)D(0)-(7)F(2)). The PL intensity increased with increasing concentration of Eu(3+) in both series. Infrared excitation was required to obtain good Raman spectra. The linear dependence of the main Raman peak wavenumber offers a non-destructive method for monitoring the substitution level and its homogeneity at the micron scale.
authors.affiliation: Institute of Nuclear Sciences Vinca, POB 522, 11001 Belgrade, Serbia. bantic@vinca.rs
authors.forename: B
authors.initials: B
authors.lastname: Antic
authors.forename: J
authors.initials: J
authors.lastname: Rogan
authors.forename: A
authors.initials: A
authors.lastname: Kremenovic
authors.forename: A S
authors.initials: AS
authors.lastname: Nikolic
authors.forename: M
authors.initials: M
authors.lastname: Vucinic-Vasic
authors.forename: D K
authors.initials: DK
authors.lastname: Bozanic
authors.forename: G F
authors.initials: GF
authors.lastname: Goya
authors.forename: P H
authors.initials: PH
authors.lastname: Colomban