Effects of ultrasonication and conventional mechanical homogenization processes on the structures and dielectric properties of BaTiO3 ceramics

The effects of the homogenization process on the structures and dielectric properties of pure and Nb-doped BaTiO3 ceramics have been investigated using an ultrasonic homogenization and conventional mechanical methods. The reagents were homogenized using an ultrasonic processor with high-intensity ultrasonic waves and using a compact mixer-shaker. The components and crystal types of the powders were determined by Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses. The complex permittivity (epsilon', epsilon'') and AC conductivity (sigma') of the samples were analyzed in a wide frequency range of 20 Hz to 2 MHz at room temperature. The structures and dielectric properties of pure and Nb-doped BaTiO3 ceramics strongly depend on the homogenization process in a solid-state reaction method. Using an ultrasonic processor with high-intensity ultrasonic waves based on acoustic cavitation phenomena can make a significant improvement in producing high-purity BaTiO3 ceramics without carbonate impurities with a small dielectric loss. (C) 2016 Elsevier B.V. All rights reserved.