Strong converse magnetoelectric effect in (Ba,Ca)(Zr,Ti)O3 - NiFe2O4 multiferroics: A relationship between phase-connectivity and interface coupling

Studying multiferroic magnetoelectrics has been a focus field for the last decade and a half, and the exploration of new materials is one of the several aspects of this quest. Here we report on the synthesis and characterization of NiFe2O4-based multiferroic composites which employ (Ba,Ca)(Zr,Ti)O3 as the ferroelectric/piezoelectric component and NiFe2O4 as the magnetostrictive phase. We find that these composites show excellent magnetoelectric properties. Especially the composite with 30 vol% of NiFe2O4 has a converse ME coefficient approximately two times larger than the previously reported one for BaTiO3-CoFe2O4 composites. A relationship between the phase connectivity within these composites and the ME properties was explored by the time of flight secondary ion mass microscopy. We believe that our investigation will be helpful for the design of magnetoelectric materials as components of sensors and memory devices.