Photoluminescence of Y3NbO7:Eu3+ powders

Abstract

Y3NbO7:xEu3+ powders (x = 0.25, 0.5, 0.75, 2, 3, 5, 10 at%) were synthesized by a two-step vibrational milling, alternating with annealing. All the samples crystallize as fluorite-type structure (space group Fm3‾m), with crystallite size 50–60 nm and show a strong orange/red luminescence with an excited state lifetime around 1.2 ms. Photoluminescence excitation and emission spectra show rapid intensity decline after 3 at% of Eu3+ content, indicating this concentration as critical for the concentration quenching, and we predicted multipolar interaction as the dominant mechanism behind it. Judd–Ofelt intensity parameters (Ω2 = 0.941∙10−20 cm2, Ω4 = 0.277∙10−20 cm2, Ω6 = 0.277∙10−20 cm2) were obtained from the excitation spectrum of Y3NbO7:3 at%Eu3+. The emission of this luminescent powder is characterized by radiative and nonradiative lifetimes of 2.3 ms and 2.4 ms, respectively, and an intrinsic quantum yield of 51.5%.