Influence of Mn on dielectric and piezoelectric properties of A-site and B-site modified PLZT nano-ceramics for sensor and actuator applications

Abstract

[Pb0.961La0.012Ba0.015Sr0.012][Zr0.53Ti0.47]0.967-(h/2)Nb0.02Zn0.01MnhO3 (PLBSZZMNT) nano-ceramics where h = 0, 0.5. 1 and 1.5 mol% fabricated through solid state reaction method has been investigated for phase formation, microstructure, density, dielectric and piezoelectric properties. X-ray diffraction studies indicated that all the samples exhibited a single-phase perovskite tetragonal structure which had strongly intensified due to the acceptor Mn content increment in the series. Our investigation with reference to isovalent (Ba2+ and Sr2+) on the A-site, pentavalent donor (Nb5+) and acceptor (Zn2+ and Mn4+) dopants on the B-site in PLZT perovskite with the stoichiometric compositional formulation tailored for dielectric and piezoelectric properties has been clearly explained. As Mn concentration increased, the grain growth enhanced, and the inter-diffusion between multiple ions promoted densification in the PLBSZZMNT nano-ceramics. TEM studies revealed an average particle size ranging from 20 to 72 nm. Dielectric characterization revealed that the eRT enhanced till 1.5 mol% Mn (2946) while the Curie temperature and dielectric loss at room temperature (Tc and TanδRT) decreased, respectively. Mn doping in PLBSZZNT induced the piezoelectric parameters (kp = 0.567) and (d33 = 486 pC/N) till 1.5 mol% Mn. Thus, 1.5 mol% Mn modified PLBSZZNT exhibits optimum dielectric and piezoelectric properties, which are suitable for possible sensor and actuator applications.