Anomalous ferroelectricity and strong magnetoelectric coupling in CoFe2O4-ferroelectric composites

Abstract

A unique averaging mechanism is established for estimation of magnetoelectric coupling coefficient (α) by studying the effect of magnetic field on ferroelectric hysteresis loop measurements. The highest value of α obtained using this mechanism is 22 mV/cm/Oe at a field of 5000 Gauss for CoFe2O4-10%BaTiO3 (CFO-10BT) composite and is in agreement with the recent reported studies. The composites of CFO-BT exhibit interplay of magnetism, ferroelectricity and display strong magnetoelectric behaviour arising out of charge disordering. The structural studies from the combination of XRD, Raman and FTIR measurements of CFO-BT composites establishco-existence of cubic and tetragonal phase with space group. The ferroelectric studies display a low leakage charge density of 0.0031 μC/cm2 and prevalent asymmetry arising due to spatial disordering of charge distribution. Furthermore, the magnetic measurements reveal an enormous increase in the coercivity of CFO-30BT composite which is identified in terms of movement of ferromagnetic domains arising due to inclusion of trapping centres of BT in CFO. © 2018 Elsevier B.V.