Evidence of direct and converse magnetoelectric coupling in eco-friendly 0.75(0.94Na0.5Bi0.5TiO3-0.06BaTiO3)–0.25(CoFe2O4) particulate composite

Abstract

Magnetoelectric (ME) multiferroic composite exhibits the ME effect, and their interaction between piezoelectric and magnetic phase is measured in terms of ME coupling (α). ME coupling is an interesting and characteristic property of ME materials and can be evaluated by direct and indirect methods. In this work, the solid-state sintering technique has been adopted to synthesize the lead-free 0.75(0.94Na0.5Bi0.5TiO3-0.06BaTiO3)–0.25CoFe2O4 (NBBT-CFO) composite. The X-ray diffraction patterns and uniform distribution of closely packed grains reveal the coexistence of constituent phases in the composite. This composite reveals room-temperature multiferroic properties. The room temperature dielectric constant (ε′) of the poled sample displays the resonance and anti-resonance peaks at a particular frequency ∼ 455 kHz and 450 kHz, respectively. The estimated value of the electromechanical coupling coefficient (kP) is 16.69%. The direct ME and converse ME coupling study has been done through the Polarization (P) vs Electric field (E) and Magnetization (M) vs Magnetic field (H) hysteresis loop measurements of magnetically and electrically poled and unpoled samples, respectively. The variation in the polarization and magnetization value reveals the presence of direct and converse ME coupling in the composite.