Solubility of Ni in BaTiO3 during co-firing

Abstract

Nickel is now frequently used as internal electrodes for multilayer ceramic capacitors (MLCC). In order to evaluate the effect of the presence of metallic Ni on the properties of BaTiO 3 -based dielectrics, nano-sized Ni particles are mixed thoroughly with BaTiO 3 powder and subsequently sintered at 1,330°C in nitrogen. The oxygen partial pressure in the nitrogen is slightly higher than the equilibrium oxygen partial pressure for the Ni→NiO reaction. Under such a condition, an upper limit of 5,400± 540 ppm for the solubility of Ni in BaTiO 3 is detected. The Ni solute acts as an acceptor to BaTiO 3 , and its presence increases the reduction resistance of BaTiO 3 significantly.

Dielectric properties, microstructure and diffuse transition of Ni-doped Ba(Zr0.2Ti0.8)O3 ceramics

“…This may be due to that while Ni content is more than 0.1 at.%, Ni located in the grain boundaries inhibits grain growth of the BZT ceramics. It is in agreement with Tuan's results that Ni at the grain boundaries can prohibit the growth of the BaTiO 3 grains [33]. Fig.…”

Electronic Conduction Mechanisms in BaTiO3–Ni Composites with Ultrafine Microstructure Obtained by Spark Plasma Sintering

“…Open porosity, however, only occurred in the composition containing 23 vol% of Ni. It has been reported that the addition of metallic Ni particles decreases the density of BaTiO 3 –Ni composites even under normal sintering conditions 23 …”

“…It has been reported that the addition of metallic Ni particles decreases the density of BaTiO 3 -Ni composites even under normal sintering conditions. 23 Representatively, the microstructures of SPSed BTNi8020 and BTNi7327 are shown in Fig. 3.…”

An experimental and theoretical study of Ni impurity centers in Ba0.8Sr0.2TiO3

“…19 The doping of barium titanate with nickel decreased the dielectric constant and the Curie temperature and also resulted in a smearing of the ferroelectric phase transition in BaTiO 3 as the Ni concentration increased. [20][21][22] The kinetics of the transformation between the cubic and hexagonal phases in BaTiO 3 doped with various impurities was studied in Ref. 14. It was shown that nickel favors the transition to the hexagonal phase, while the doping of BaTiO 3 with strontium prevents this transition.…”