Bi4Ti3O12

Bi4Ti3O12, also known as bismuth titanate, is a perovskite-structured material with the chemical formula Bi4Ti3O12. It is a member of the bismuth titanate family, which includes other compounds like Bi4Ti3O12 and Bi3TiNbO9. This compound is notable for its ferroelectric and piezoelectric properties, making it useful in various applications such as sensors, actuators, and non-volatile memory devices.

The crystal structure of Bi4Ti3O12 is characterized by a distorted perovskite lattice, where bismuth (Bi) and titanium (Ti) ions occupy the A and B sites, respectively, and oxygen (O) ions form the octahedral network. The distortion in the lattice is due to the large size of the Bi3+ ion, which leads to a tetragonal structure at room temperature.

Bi4Ti3O12 exhibits a ferroelectric phase transition at a critical temperature, typically around 700°C. Below this temperature, the material displays spontaneous polarization, which can be switched by an external electric field. This property makes it suitable for applications in ferroelectric random-access memory (FeRAM) and other non-volatile memory devices.

The piezoelectric properties of Bi4Ti3O12 arise from the coupling between mechanical stress and electrical polarization. This makes it useful in sensor and actuator applications, where it can convert mechanical energy into electrical energy and vice versa.

Despite its promising properties, Bi4Ti3O12 has some limitations, such as its high leakage current and low breakdown voltage, which can affect its performance in certain applications. Ongoing research aims to address these issues and further enhance the properties of this material for various technological applications.