Preparation and characterization of BaTiO3–natural muscovite composites

Natural muscovite (nM) exhibiting magnetic vortex states are ball milled into fine powder and mixed in different relative ratios (weight %) with ferroelectric barium titanate (BaTiO3) synthesized by solid-state reaction. The mixture is ball milled and pressed into pellets and then sintered at 600 °C for 2 h. The composite samples of formula, (1 − x)BaTiO3-(x)nM, where x = 0.1, 0.2, 0.3 are prepared for studying its multifunctional properties. The composite samples are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, dielectric spectroscopy, ferroelectric polarization and magnetization measurements performed at room temperature. The XRD studies confirm the presence of only the constituent ferroelectric BaTiO3 and ferromagnetic nM phases and no other additional phases. The dielectric constant of the prepared (1 − x)BaTiO3-(x)nM composites exhibits relatively least dispersion at higher frequencies (> 100 kHz). Further, the composite samples exhibit ferroelectric polarization hysteresis and also considerable leakage current which is explainable by the space charge limited conduction (SCLC) mechanism. Out of the three composite samples, 0.7BaTiO3–0.3 nM shows ferromagnetic behavior with signatures for the presence of magnetic vortex states that is similar to that of the pure nM single crystal sheets.