THE OVERVIEW OF BARIUM TITANATE PROPERTIES AND APPLICATION OPPORTUNITIES

Abstract

Barium titanate (BT) is a ferroelectric material with a perovskite structure important in the field of electronics. Due to high flexiblity of its crystal lattice it has the capabilty to host ions with different oxidation state and careful selection of dopants could enable tailoring of barium titanate structure and electrical properties. Barium titanate doped with La, Sb, Sm, Nb and Mn will be presented in the light of structural changes and their influence on electrical properties modification. Doping with La, Sb and Sm in very low concentrations induces symmetry change from tatragonal to pseudo-cubic. La, Sb, Nb and Sm are proven to be grain growth inhibitors, with the different effect on obtained ceramics density. Dielectric permittivity value was significantly changed depending on dopant kind and concentration. Partial substitution of Ba or Ti ions by some of this dopants induced the movement of phase transition peaks to the lower temperatures and caused the formation of diffuse phase transition. In this way, the application of barium titanate can be widened from capacitors to PTCR sensors, gas and humidity sensors, etc. In the recent years, there is a growing interest for multiferroic materials with barium titanate as a main component. When being mixed with ferrites in the multiferroic composites the electrical properties of barium titanate are being compromised. Dielectric permittivity starts to decrease in comparison with pure BT ferroelectric material. Using of doped barium titanate as a part of the multiferroic material could enhance the overall dielectric permittivity of barium titanate and therefore the dielectric properties of the multiferroic material. Mixing route was used for the preparation of BaTiO3-NiFe2O4, BaTiO3-NiZnFe2O4, Ba(Sb)TiO3- NiFe2O4 composite materials. Magnetic and electrical properties of multiferroic materials have shown the dilution effect due to existence of both, ferroelectric and ferrite phases in the samematerial.