Barium titanate (BaTiO3, short for BTO) is one of the most important ferroelectric materials, used in many electronic applications such as ferroelectric access memories random and multilayer ceramic capacitors. (MLCC), ferroelectric random access memories (FRAM), and also because of its excellent and large dielectric, piezoelectric and ferroelectric properties, it has many important applications. Barium titanate is the first piezoelectric transducer ceramic ever developed and it has the same structure as the mineral named Perovskites (ieCaTiO3) and is therefore also known as "Perovskite". Above its Curie temperature (around 125°C), the unit cell is cubic [4]. Below the Curie point, the structure is slightly deformed to take the tetragonal shape with a dipole moment along the c direction. Other transformations occur at temperatures near 0˚C and -80˚C: below 0˚C, the unit cell is orthorhombic with the polar axis parallel to the face diagonal and below -80 ˚C, it is rhombohedral with the polar axis along a body diagonal. A typical ABO3 type unit cell structure is given in Fig...4. ...