Magnetodielectric coupling in barium titanate–cobalt ferrite composites obtained via thermally-assisted high-energy ball milling

In this work, a magnetodielectric coupling observed in barium titanate–cobalt ferrite composites synthesized using high-energy ball milling assisted via a thermal treatment is discussed. Vibrating sample magnetometry and dielectric spectroscopy showed that multiferroic composites possess both ferromagnetic and dielectric behaviors inherited from the parent ferromagnetic cobalt ferrite and ferroelectric barium titanate phases. The magnetocapacitance (up to 35%) recorded for x = 0.3, (1-x)BaTiO₃–xCoFe₂O₄, can be attributed to the spin-dependent filtering mechanism. The composite with the aforementioned composition exhibited a homogeneous matrix–particle composite microstructure, which was achieved via high-energy ball milling during the mixing stage.