Electrical properties of BiFeO3–BaTiO3 ceramics fabricated by mechanochemical synthesis and spark plasma sintering

0.75BiFeO3–0.25BaTiO3 (75BF–25BT) multiferroic powders were prepared by a mechanochemical synthesis at room temperature and the dense ceramics were sintered by a spark plasma sintering (SPS) at 1023–1073 K. Microstructures of the ball milled powders and SPS ceramics were thoroughly investigated through X-ray diffraction and scanning electron microscopy, respectively. A bulk density up to 96% of theoretical density was achieved in the SPS ceramics. Dielectric spectra of the 75BF–25BT ceramics were characterized in a broad range of temperature and frequency. Typical saturated ferroelectric hysteresis loops with remnant polarization of 10 μC/cm2 were obtained at room temperature, which makes it a good candidate for potential applications.

► High density BiFeO3–BaTiO3 ceramics by a new mechanochemical synthesis combined with spark plasma sintering (SPS) were investigated. ► Studied electrical properties of BiFeO3–BaTiO3 ceramics after vacuum annealing treatment at appropriate temperature. ► Substitution of BaTiO3 eliminated a small usual impurity phase in BiFeO3. ► Dielectric properties were enhanced by the mechanochemical synthesis and spark plasma sintering. ► Curie-temperature Tc, remanent polarization Pr, and piezoelectric constant d33 of the ceramics were investigated.