Barium titanate is an oxide of barium and titanium. Molecular Weight: 233.192 g /mol. It is a ferroelectric ceramic material, with a photorefractive effect and piezoelectric properties.
Barium titanate is used as a dielectric material for ceramic capacitors, and as a piezoelectric material for microphones and other transducers.
Barium titanate is used as a true breakthrough material in the electronic ceramics industry for more than half a century, barium titanate (BaTiO3) has found widespread use in multi-layer ceramic capacitors (MLCCs), piezoelectric & ferroelectric components, embedded decoupling capacitors (EDC), PTC thermistors, ceramic filters, etc.
In the pure form it is an electrical insulator. However, when doped with small amounts of metals, most notably scandium, yttrium, neodymium, samarium etc it becomes semiconducting.
At the Curie temperature, barium titanate undergoes a phase change from tetrahedral to cubic. It has also been reported that single crystals of barium titanate exhibit negative temperature co-efficient of resistivity (NTCR) properties.
The solid can exist in five phases, listing from high temperature to low temperature: hexagonal, cubic, tetragonal, orthorhombic, and rhombohedral crystal structure. All of the phases exhibit the ferroelectric effect except the cubic phase.
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