Effects of Mg Addition on Phase Transition and Dielectric Properties of Ba(Zr0.05Ti0.95)O3 System
A. Quintana-Nedelcos*, 1, A. Fundora2, H. Amorín3 , J.M. Siqueiros4
1 Instituto Superior Politécnico “José A. Echeverría” (CUJAE), Calle 114, Num 11901, Marianao C. Habana, CP 10400, Cuba
2 Instituto de Ciencias y Tecnología de Materiales (IMRE), Universidad de La Habana, San Lázaro y L, Vedado, CP 10400, Cuba
3 Instituto de Ciencias de Materiales de Madrid, CSIC, Cantoblanco, 28049, Madrid, Spain
4 Centro de Ciencias de la Materia Condensada, Universidad Nacional Autónoma de México, Apartado Postal 2681, Ensenada, Baja California, 22800, México
Samples were prepared by conventional powder mixing procedure. The starting powder MgCO3, BaCO3, TiO2 and ZrO2 (ALFA AESAR 99.9% pure) was weighed according to the formula (1-x) BaCO3 + x MgCO3 + 0.95TiO2 + 0.05ZrO2. x was varied from 0.025, 0.050 and 0.075. The XRD study at room temperature suggests that ceramics have pseudo cubic symmetry phase. The behavior of the measured dielectric permittivity and dielectric loss with temperature and frequency reveals that the materials undergo a diffuse para-ferroelectric phase transition and are of the relaxor type. The dielectric properties corresponding to our samples show very low remnant polarization in their hysteresis loop, this result can be explained by the substitution of ion Ba2+ by Mg2+, having both a large difference in their respective ionic size, with a disorder in the structure of the system, also in site B we have two different elements (Zr and Ti), in consequence of both kind of structural defects we have a weakness in long terms of dipolar interaction, reducing the stability of the ferroelectric phase. In the sample obtained with a higher grain size, a presence of an anti-ferroelectric phase is suggested, while in the others two samples this result it is not appreciable, due to their very small grain size, but a very thin hysteric loop was a result of depressed ferroelectric behavior.
open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http: //creativecommons.org/licenses/by-nc/3.0/ which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.