Photoluminescence, cathodoluminescence and micro-Raman investigations of monoclinic nanometre-sized Y<inf>2</inf>O<inf>3</inf> and Y<inf>2</inf>O<inf>3</inf>:Eu³⁺

Abstract

Copyright © The Author(s) 2016. Herein we describe a large scale synthesis of nanosized, monoclinic Y2O3 and Y2O3:Eu3+ with 2 mol% Eu3+ in a plasma-discharge chamber. This high yield synthesis provided nanosized particles with dimensions between 5 nm to 50 nm, which were stable during shelf life at ambient conditions for more than 6 years. We assume that the Gibbs–Thomson effect is responsible for this unexpected high stability. Annealing at 950 1C completely transformed the monoclinic particles into the cubic phase, which was indicated by the photo- and cathodoluminescence emission spectra in addition to the much stronger light output. The undoped Y2O3 material was contaminated with Dy3+, which showed characteristic and rather strong luminescence upon activation with a He–Ne laser at 632.8 nm, both at the Stokes and anti-Stokes side. Photoluminescence, cathodoluminescence and Raman spectra of the undoped and doped monoclinic nanocrystals were recorded and partially interpreted.