Effect of Mn addition on magnetoelectric coupling behavior of BiFeO3-Pb/BaTiO3 multiferroics

Abstract

Hybrid multiferroic materials exhibiting morphotropic phase boundary (MPB) with enhanced ferroelectric and ferromagnetic properties has shown great potential for future technologies. In this paper, we report structural, ferroelectric, piezoelectric, magnetic and magnetoelectric characteristics of 0.7BiFeO3-0.3Pb0.5Ba0.5TiO3 (BFPTBT-Pure) and 0.7BiFeO3-0.3Pb0.5Ba0.5TiO3 + Mn0.5% (BFPTBT-Mn5%) ceramic compositions synthesized via conventional solid state reaction route. The crystallinity of the compositions exhibits polymorphs of rhombohedral (R3c) and tetragonal (P4mm) symmetries forming morphotropic phase boundary (MPB). Highly dense SEM micrographs were observed with an average grain size 0.57 μm and 0.62μm for BFPTBT-Pure and BFPTBT-Mn5%, respectively. Mn doped ceramic sample. Improved ferroelectric behavior has been observed with Mn doping in the composition as the value of remnant polarization increases from 2.46 μC cm-2 to 7.63 μC cm-2 recorded at an applied frequency of 50 Hz. The piezoelectric coefficients for BFPTBT-Pure and BFPTBT-Mn5% were found to be 36pC/N and 57pC/N respectively. M-H hysteresis loops depicted that remnant magnetization increases with Mn addition in the sample. The Curie transition temperature (T c) was observed to be 447 °C and 467 °C for BFPTBT-Pure and BFPTBT-Mn5% ceramics, respectively. The magnetoelectric coupling was confirmed through the observation of magnetic field induced relative change in dielectric constant (Magnetocapacitance: MC). MC was found to be 9.49% and 11.81% for BFPTBT-Pure and BFPTBT-Mn5%, respectively.