Barium titanate is a ferroelectric ceramic material, with piezoelectric properties and a photorefractive effect. It can exist as a white powder, be transparent as larger crystals, or remain in five phases of solid form, listing from high temperature to low temperature: hexagonal, cubic, tetragonal, orthorhombic, and rhombohedral crystal structures.
Produced by heating titanium dioxide and barium carbonate, there is a progressive reaction through liquid phase sintering.
Barium titanate experiences two-phase conversions that alter the volume and crystal shape. This phase alteration produces composites in which the barium titanates possesses a negative bulk modulus (Young’s modulus), signifying that when an energy responds to the additions, there is then a shifting in a different course, additionally hardening the fusion.
NOTE: As is in numerous oxides, barium titanate is insoluble in water but attacked by sulfuric acid.