Lattice parameter and luminescence properties of europium activated yttrium oxide M.V. Nazarov a, * , J.H. Kang a , D.Y. Jeon a , E.-J. Popovici b , L. Muresan b , B.S. Tsukerblat c a Department of Material Science and Engineering, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701, South Korea b Raluca Ripan Institute of Chemistry, Cluj-Napoca, Romania c Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel Received 7 September 2004; received in revised form 13 October 2004; accepted 14 October 2004 by B. Jusserand Available online 27 October 2004 Abstract Samples of yttrium oxide doped with trivalent europium have been prepared by ceramic techniques, under different synthesis conditions; barium chloride (BaCl 2 ) and sodium tetraborate (Na 2 B 4 O 7 ) were tested as flux. The improvement of luminescence properties in dependence on substitution of Eu 3C for Y 3C in the host lattice, under electron and UV excitations is demonstrated. The lattice parameter as a quantitative assessment of activator incorporation degree is proposed. The obtained results are discussed with respect to the employed processing method. q 2004 Elsevier Ltd. All rights reserved. PACS: 78.55.Km; Keywords: A. Phosphor; A. Y 2 O 3 :Eu; D. Optical properties; E. Luminescence 1. Introduction There is a long interest in red emitting europium- activated yttrium oxide (Y 2 O 3 :Eu) both as a commercial phosphor and as a model system for the study of the effect of the interplay of radiative and nonradiative processes on phosphor efficiency [1–10]. The main applications of Y 2 O 3 :Eu as commercial phosphor are in lighting and cathode ray tube, display material, in tricolor fluorescent lamps, field emission displays and laser devices. Because of such large applications the further investigations of Y 2 O 3 :Eu and improvement it properties is desirable. The aim of this work is to synthesize europium-activated yttrium oxide phosphor with improved luminescence properties and to investigate these properties in dependence with their synthesis conditions. In order to enhance the luminescence of Y 2 O 3 :Eu, the thermal treatment in the presence of barium chloride (BaCl 2 ) and sodium tetraborate (Na 2 B 4 O 7 ) as flux is suggested. One attempt is also made to explain the photoluminescence (PL) experimental data by proposing a lattice parameter (LP) as a quantitative assessment of activator incorporation degree (AID). The term AID is used to define the ability of europium to efficiently substitute yttrium from the host lattice [11]. 2. Experimental Phosphor samples were characterized by crystalline structure and luminescence properties. Particle sizes and morphologies of the investigated phosphors were deter- mined by scanning electron microscope (SEM) Philips- XL30SFEG. To control the particle size and to find the size 0038-1098/$ - see front matter q 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.ssc.2004.10.021 Solid State Communications 133 (2005) 183–186 www.elsevier.com/locate/ssc * Corresponding author. Tel.: C82 42 864 2154; fax: C82 42 869 3310. E-mail address: nazarov@kaist.ac.kr (M.V. Nazarov).