Structure and properties of plasma sprayed BaTiO3 coatings after thermal posttreatment

Previously published results on electrical and mechanical properties of BaTiO3 coatings prepared by atmospheric plasma spraying showed anomalies in their dielectric response. This paper provides a study of electrical and mechanical properties of BaTiO3 coatings after thermal posttreatment. The spraying was carried out by a direct current gas-stabilized plasma gun. BaTiO3 was fed into the plasma jet as a feedstock powder prepared by reactive sintering of micrometer-sized powders of BaCO3 and TiO2. In the next step the coatings were annealed in air. Microstructure and phase composition are reported and discussed in relation to electric and mechanical properties. Dielectric properties are reported for the radio frequency (RF) range.