Uses
Barium titanate is a dielectric ceramic used for capacitors. It is a piezoelectric material for microphones and other transducers. The spontaneous polarization of barium titanate is about 0.15 C/m2 at room temperature and its Curie point is 120 °C. As a piezoelectric material, it was largely replaced by lead zirconate titanate, also known as PZT. Polycrystalline barium titanate displays positive temperature coefficient, making it a useful material for thermistors and self-regulating electric heating systems.
Barium titanate crystals find use in nonlinear optics. The material has high beam-coupling gain, and can be operated at visible and near-infrared wavelengths. It has the highest reflectivity of the materials used for self-pumped phase conjugation (SPPC) applications. It can be used for continuous-wave four-wave mixing with milliwatt-range optical power. For photorefractive applications, barium titanate can be doped by various other elements, e.g. iron.
Thin films of barium titanate display electrooptic modulation to frequencies over 40 GHz.
The pyroelectric and ferroelectric properties of barium titanate are used in some types of uncooled sensors for thermal cameras.
High purity barium titanate powder is reported to be a key component of new barium titanate capacitor energy storage systems for use in electric vehicles.
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