Magnetoelectric ceramic composites prepared by spark plasma sintering with notably enhanced magnetoelectric effect

CoFe2O4 (CFO)/BaTiO3 (BTO) magnetoelectric (ME) ceramic composites were prepared by spark plasma sintering (SPS) with mechanically mixed powders. The unwanted phases, atomic interdiffusion and microcracks emerged in the conventional sintering process were prevented in the SPS process. The CFO/BTO ceramics showed great densities measured by the Archimedes method. In this paper, the ferromagnetic, ferroelectric, and ME properties of the ceramic composites were well studied. The strongly optimized ME voltage coefficient up to as high as 180 mV/cm Oe was obtained in the spark plasma sintered CFO/BTO ceramics. The theoretical ME voltage coefficients of the ceramics were also calculated by the finite-element method. The reasons for the improvement of the ME voltage coefficient and the lower experimental ME value comparing to the calculations were both discussed in this paper.