title: Effect of structure, particle size and relative concentration of Eu(3+) and Tb(3+) ions on the luminescence properties of Eu(3+) co-doped Y(2)O(3):Tb nanoparticles.
abstract: Eu(3+) co-doped Y(2)O(3):Tb nanoparticles were prepared by the combustion method and characterized for their structural and luminescence properties as a function of annealing temperatures and relative concentration of Eu(3+) and Tb(3+) ions. For Y(2)O(3):Eu,Tb nanoparticles annealed at 600 and 1200 °C, variation in the relative intensity of excitation transitions between the (7)F(6) ground state and low spin and high spin 4f(7)5d(1) excited states of Tb(3+) is explained due to the combined effect of distortion around Y(3+)/Tb(3+) in YO(6)/TbO(6) polyhedra and the size of the nanoparticles. Increase in relative intensity of the 285 nm peak (spin-allowed transition denoted as peak B) with respect to the 310 nm peak (spin-forbidden transition denoted as peak A) with decrease of Tb(3+) concentration in the Y(2)O(3):Eu,Tb nanoparticles heated at 1200 °C is explained based on two competing effects, namely energy transfer from Tb(3+) to Eu(3+) ions and quenching among the Tb(3+) ions. Back energy transfer from Tb(3+) to Eu(3+) in these nanoparticles is found to be very poor.
authors.affiliation: Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
authors.forename: S
authors.initials: S
authors.lastname: Mukherjee
authors.forename: V
authors.initials: V
authors.lastname: Sudarsan
authors.forename: R K
authors.initials: RK
authors.lastname: Vatsa
authors.forename: S V
authors.initials: SV
authors.lastname: Godbole
authors.forename: R M
authors.initials: RM
authors.lastname: Kadam
authors.forename: U M
authors.initials: UM
authors.lastname: Bhatta
authors.forename: A K
authors.initials: AK
authors.lastname: Tyagi