Magnetoelectric effect of the multilayered CoFe2O4/BaTiO3 composites fabricated by tape casting

This paper presents the structural, ferroelectric, ferromagnetic, resonance and magnetoelectric (ME) properties of multilayered ME composites fabricated using tape casting method. The compositions corresponding to CoFe2O4 (CFO) with particle size of similar to 150 nm and BaTiO3 (BTO) with particle size of similar to 100 nm were chosen as ferromagnetic and ferroelectric phases, respectively. Delamination was found at the interface between CFO and BTO layers, which was related to the residual stress due to the difference in thermal expansion coefficient between the two layers. The largest direct magnetoelectric and converse magnetoelectric coefficients of the multilayered ME composite were, respectively, 36 mu V/cm Oe at a bias magnetic field of 2,800 Oe and 1.16 x 10(-3) G/V at a frequency of 30 kHz. In addition, the corresponding interfacial coupling coefficient was calculated to be 3.2 x 10(-5). For the multilayered ME composite, a resonance frequency of 4.96 MHz and a bandwidth of 40 kHz were obtained using capacitance-frequency spectrum method.