Synthesis, sintering and dielectric properties of a BaTiO3–Ni composite

Barium titanate–nickel composites (BaTiO3–Ni) were synthesized at a low temperature using a sol–gel method and sintered in a reducing atmosphere. XRD, FE-SEM, Raman spectroscopy and TGA were performed to confirm the phases of BaTiO3 and Ni, the morphology and tetragonal crystal structure of BaTiO3 and the weight loss. The results indicate that by controlling the experimental conditions (temperature and atmosphere) during the sintering process, the grain size of the BaTiO3–Ni composite can be controlled. The average grain size of the dense BaTiO3–Ni composite was in the range of 0.6–1.5 µm. In addition, the dielectric constant increased from ~2000 for monolithic BaTiO3 to ~11,000 by increasing the Ni content. The enhanced dielectric properties of the BaTiO3–Ni composite are due to the well-dispersed nickel particles in the BaTiO3 matrix.