Relaxor properties of Ba1-xNaxTi1-xNbxO3 at low temperatures

Purpose: The purpose of this paper is to investigate ferroelectric relaxor behavior of polycrystalline solid solutions of Ba1-xNaxTi1-xNbxO3 (for x = 0.3 and x = 0.4) at low temperatures (113 K - 473 K). Design/methodology/approach: The dielectric spectroscopy method has been applied to measure dielectric and electric parameters within the frequencies from 20 Hz to 1 MHz. Findings: Temperature dependences of real (ε') and imaginary (ε'') parts of dielectric permittivity confirm relaxor type of polarization behavior for both investigated materials. Experimental findings are in good agreement with data published in literature. Diffused phase transition of relaxor character is analysed in the terms of departure from Curie-Weiss rule. A dependence of the temperature related to the maximum of dielectric permittivity on the frequency has activated character. Different thermal activation energies found for the investigated materials may be related to their different microstructures. Research limitations/implications: Further investigations should be carried on in a broaden frequency range (up to 1.8 GHz) in order to establish an influence of network dynamics on ferroelectric-paraelectric phase transition. Originality/value: Relaxor behaviour in polycrystalline solid solution of Ba1-xNaxTi1-xNbxO3 (for x = 0.3 and x = 0.4) is described.