Percolative effects and giant dielectric tunability of BaTiO3―LuFe2O4 composites

Abstract We report on exotic dielectric properties of composite materials consisting of traditional ferroelectric BaTiO 3 and electronic ferroelectric LuFe 2 O 4 . The composites were synthesized by a simple ceramic processing method with properties that can be tailored by adjusting LuFe 2 O 4 concentration. A percolative effect was observed at the volume fraction of ∼0.26, which led to an abrupt increase in the dielectric permittivity. For composites with high LuFe 2 O 4 fractions, a giant dielectric tunability was observed over a broad temperature interval, which is in strong contrast to traditional ferroelectrics.