Investigation of magnetoelectric effect in Bi0.5Na0.5TiO3–CoMn0.2Fe1.8O4 composites

Abstract

In the present work Bi 0.5 Na 0.5 TiO 3 (BNT) and CoMn 0.2 Fe 1.8 O 4 (CMFO) composites, (1-x) BNT/(x) CMFO with x = 0.10, 0.20, 0.30, 0.40 and 0.50 have been synthesized using solid state reaction method. X-ray diffraction exhibits the peaks akin to constituent BNT and CMFO phases suggesting the effective development of the desired composites. The variation of dielectric constant with temperature reveals their diffuse phase transition behaviour and existence of two dielectric anomalies in vicinity of ferroelectric to antiferroelectric and from antiferroelectric to paraelectric transition temperatures. Remnant polarization (2P r ) and Coercive field (2E C ) found to decrease with addition of CMFO. Furthermore, magnetization vs. magnetic field (M-H) hysteresis loops shows an increment in magnetization with increase in CMFO content. Complex impedance spectroscopy confirms the existence of grain (bulk) effect and temperature dependent electrical relaxation processes in the composites. Magnetoelectric analysis shows maximum magnetoelectric voltage coefficient, α ME for x = 0.10 and the value of, α ME decreases from 6.765 mV/cm-Oe to 2.780 mV/cm-Oe for the composites x = 0.10 to 0.50.