Effect of interface recombination on magnetoelectric coupling in CoFe2O4-BaTiO3 composites

The (1−x)CoFe2O4+xBaTiO3 (x=0.5) magnetoelectric(ME) nano-powders were prepared by molten salt synthesis method and the corresponding ceramics were sintered. The morphology and structure of as-prepared powders and ceramics were characterized and studied systematically by using XRD, SEM and EDX. In particles, the two phases, CoFe2O4 and BaTiO3, are symbiotic with nano-scale coordinate lattice. A considerable ME coefficient(αE) of about 15.96 mV/A is observed in the x=0.5 ME ceramic, which is attributed to the better interface sintered by using those nano-particles with the two phases and a correct poling strategy on the sample. But the interface between the phases has gone through a separating and recombinating during their sintering process. A two-time sintering process was also performed on those ceramics while the αE of the x=0.5 two-time sintered ceramic drops to 67.7 μV/A, which could be explained by the split of the interface during the recombination in the ceramics preparation.