Improved and delayed radiative emission response of Eu-doped BaTiO₃ nanoscale system

¹ Nanoscience and Soft Matter Laboratory, Department of Physics, Tezpur University, Tezpur - 784 028, Assam, India
² Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata - 700 064, India
³ Department of Physics, University of Calcutta, 92 Acharya Prafulla Chandra Road, Kolkata - 700 009, India

^a e-mail: best@tezu.ernet.in
^b e-mail: cujanad@yahoo.com

Received: 23 March 2012
Revised: 2 June 2012
Accepted: 6 June 2012
Published online: 11 July 2012

Abstract

We report on the structural, spectroscopic and radiative emission characteristics of Eu-doped BaTiO₃ (BT) nanosystem as compared to the pure BT system. The structural analysis was performed by X-ray diffraction (XRD) studies where the nanoscale BT sample exhibits a perovskite structure with most intense peak along (1 1 0) plane that depicts the preferred crystallographic orientation. Also, the diffraction peak intensity was found to be suppressed for Eu-doped BT nanosystem. The nature of radiative emission was evaluated via steady-state photoluminescence spectroscopy (PL) and positron annihilation spectroscopy (PAS). The improved radiative emission response, with Eu²⁺ doping, was believed to be accompanied by 4f⁶5d→4f⁷ transitions in case of Eu-doped BT system. Whereas, PAS lifetime study of doped sample has revealed longer lifetimes indicating thereby partial substitution of Ti⁴⁺ by Eu²⁺ in BaTiO₃ system.