Preparation and characterization of (1 – y)BiFeO₃/y(Ba_0.7Na_0.3Ti_0.7Nb_0.3)O₃ multiferroic ceramics

Laboratoire des Matériaux Ferroélectriques (LMF), Unité de Physique-Mathématiques 05UR15-04, Faculté des Sciences de Sfax (FSS), Route de Soukra km 3, 3000 Sfax, Tunisia

^a e-mail: jarbouiahmed@yahoo.fr

Received: 18 June 2012
Revised: 5 November 2012
Accepted: 14 January 2013
Published online: 2 April 2013

Abstract

We present in this work a contribution to the study of the solid solution (1 – y)BiFeO₃/y(Ba_0.7Na_0.3Ti_0.7Nb_0.3)O₃. Room temperature X-ray diffraction patterns for some prepared compositions confirmed the formation of perovskite structure. The study of the evolution of dielectric properties as a function of sintering temperature allowed us to determine the optimum conditions that minimize the presence of defects and oxygen stoichiometric limit fluctuations due to the volatility of bismuth. The variation of permittivity as a function of temperature and frequency for the (1 – y)BiFeO₃/y(Ba_0.7Na_0.3Ti_0.7Nb_0.3)O₃ solid solution was measured. The effect of Ba_0.7Na_0.3Ti_0.7Nb_0.3O₃ addition content on crystal structure, dielectric and magnetic properties of BiFeO₃ was investigated. Raman measurements reveal resonant enhancement of two-phonon excitation for (1 – y)BiFeO₃/y(Ba_0.7Na_0.3Ti_0.7Nb_0.3)O₃ samples. We also expect that the solid solution shows weak ferromagnetic behavior for low Ba_0.7Na_0.3Ti_0.7Nb_0.3O₃ levels of substitution.