A Ferroelectric Ferromagnetic Composite Material with Significant Permeability and Permittivity

Composite materials containing both ferroelectric and ferromagnetic phases have been synthesized from nanometer‐sized powders of BaTiO3 (ferroelectric phase) and NiCuZn ferrite (ferromagnetic phase) by a standard ceramic method. The coexistence of magnetic and electric hysteresis in the composite material has been observed at room temperature. Upon the application of magnetic and electric fields, the magnetization and electric polarization of the composite material can easily be tuned based on the changing BaTiO3 content of the materials studied. These composite materials exhibit both excellent dielectric and soft‐magnetic properties with a variation of the frequency. Our results strongly suggest that this composite material may be the best candidate for the development of truly integrated passive filters. Due to the combination of both inductance and capacitance in one material, the adoption of an integrated passive filter could greatly reduce the size of printed circuit boards and could efficiently suppress electromagnetic interference, thereby enabling significant miniaturization of electronic elements and devices. A novel composite with coexistent ferroelectric and ferromagnetic phases has been prepared using a standard ceramic method. Both high dielectric constant and high magnetic permeability (see Figure) are shown in the xBaTiO3‐(1 – x)Ni0.2Cu0.2Zn0.6Fe1.96O4 material, which is significant for the integration of passive components.