Enhanced mechanical and dielectric behavior of BaTiO3/Cu composites

BaTiO3/xCu composite ceramics with x = 0–30 wt.% were fabricated by the traditional mixing method in nitrogen gas. The mechanical properties and electric properties of the obtained composites were investigated as a function of the Cu mass fraction using a three bending test and impedance spectroscopy. The results indicated that the relative density of the sintered composites reached above 91%, the Cu-dispersed BaTiO3 composites enhanced the mechanical properties, particularly the high fracture toughness (∼3.9 MPa m1/2) and bending strength (∼134 MPa), compared to the monolithic BaTiO3. Furthermore, the percolation threshold of BaTiO3/Cu composites was x = 25 wt.%. The permittivity (ɛr) markedly increased from ∼2000 for monolithic BaTiO3 to ∼9000 with increasing Cu up to 30 wt.%. Additionally, the temperature coefficient of this system was less than 5% in the temperature range of 25–115.