title: Combustion Synthesized Europium Doped LaAI₁₁O₁₈ Phosphors--An Electron Paramagnetic Resonance and Optical Study.
abstract: By adopting a facile solution combustion synthesis, crystallized europium doped blue phosphors were successfully prepared. These phosphors were characterized by X-ray diffraction (XRD), Fourier transform infrared absorption (FT-IR), energy dispersive analysis of X-ray, Electron Paramagnetic Resonance (EPR) and Photoluminescence (PL) experimental methods. The photoluminescence spectrum indicates Eu²⁺ and Eu³⁺ ions in these phosphors. The band at around 442 nm is attributed to the spin-allowed 4f⁶5d¹ (2D) --> 4f⁷(⁸S₇/2) transition of Eu²⁺ ions. The sharp bands at 591 (⁵D₀ --> ⁷F₁) and 616 (⁵D₀ --> ⁷F₂) nm are attributed to the spin-forbidden transitions of Eu³⁺ ions. The EPR spectra of as-prepared and post-treated LaAl₁₁O₁₈:Eu phosphors exhibit signals characteristic of La²⁺ and Eu²⁺ ions. The number of spins, Gibbs energy, magnetic susceptibility, Curie constant and effective magnetic moment values were calculated and compared at 296 and 110 K.
authors.forename: Vijay
authors.initials: V
authors.lastname: Singh
authors.forename: G
authors.initials: G
authors.lastname: Sivaramaiah
authors.forename: J L
authors.initials: JL
authors.lastname: Rao
authors.forename: R Senthil
authors.initials: RS
authors.lastname: Kumaran
authors.forename: S J
authors.initials: SJ
authors.lastname: Dhoble