Sintering and Dielectric Properties of Hydrothermally Synthesized Cubic and Tetragonal BaTiO₃ Powders

Abstract

The sintering behavior of hydrothermally synthesized cubic and tetragonal BaTiO3 powders was studied as a function of temperature. In addition, the dielectric properties of the sintered samples were examined from room temperature to 200°C at a frequency of 1 kHz. The influence of powder characteristics and sintering temperature on the microstructure development and dielectric properties were investigated. It was found that tetragonal powders showed limited grain growth and higher final density upon sintering, whereas the cubic powder exhibited abnormal grain growth and lower density. This was attributed to more disperse and homogeneous particles in the tetragonal powders with fewer defects, as compared to the cubic powder. Correlations between the microstructure and the dielectric properties were developed. As expected, samples with finer grain size and higher density exhibited higher dielectric constant and lower loss.

Dielectric and ferroelectric properties of BST ceramics obtained by a hydrothermally assisted complex polymerization method

“…Crystal symmetry and tetragonality, determine the dielectric and ferroelectric properties of the BST ceramic. Zhu et al [25] found that tetragonal BaTiO 3 powders have better sintering behavior and higher dielectric constant than cubic-phase powders. Only BST ceramics in tetragonal symmetry exhibit ferroelectric properties.…”

Electrical and structural characterization of PTCR pure BaTiO3 nanopowders synthesized by sol–gel emulsion technique

“…With the decreasing particle size, the smaller domain sizes may have forced the unit cells to have pseudocubic symmetry resulting in the percentage of the tetragonal phase to reduce and that of the cubic phase to increase [17,34]. Tetragonal BaTiO 3 powders are known to have higher density due to better sintering behaviour and larger permittivity values than the cubic powders that leads to their applications in MLCC [45]. However the paraelectric phase of BaTiO 3 shows better temperature stability of the dielectric constant at low temperatures at low AC field [40].…”

Synthesis of monodispersed barium titanate nanocrytals—hydrothermal recrystallization of BaTiO3 nanospheres

“…capacitors, especially for the manufacture of multilayer ceramic capacitors (MLCCs) [1][2][3]. With the miniaturization of electronic devices, the present trend is to further increase the performances of the devices: higher capacitance (up to 100 mF) coupled with smaller size.…”