Structural, dielectric, ferroelectric, and electromechanical performance of Mn modified (BaCa)(ZrTi)O3 ceramics

Abstract

Lead-free (Ba0.85Ca0.15)(Zr0.1Ti0.9)1-xMnxO3 [x = 0.01,0.02,0.03,0.04,0.05] ceramics were prepared by conventional solid-state reaction method. The structural evaluation was analyzed by the X-ray diffraction and Rietveld refinement, which illustrate that all the compositions exhibit dual phase crystal structure i.e., tetragonal + orthorhombic with space group P4mm+ Amm2. The surface morphology was studied using the scanning electron microscope and it is found that Mn doping modifies the grain size. The temperature and frequency-dependent dielectric study show that the dielectric constant reduces with an increase in Mn content. The lowering of the Curie temperature is also observed with an increase in Mn doping percentage. A well-saturated ferroelectric loop is obtained for all compositions with a reduction in the remnant polarization and coercive electric field. The direct piezoelectric coefficient was measured by the quasi-static method for all the compositions. The elastic compliances and piezoelectric and coupling parameters of all the compositions were calculated using the resonance and anti-resonance technique. The figure of merit concerning energy harvesting was calculated using the parameters obtained from the resonance and anti-resonance measurement. The high value of elastic, piezoelectric, and coupling parameters makes the composition suitable for harvesting application.