Barium titanate micron and nano powder

CAS no. : 12047-27-7
EINECS no. : 234-975-0
Molecular formula: Ba2O4Ti
Molecular weight: 386.5186
Melting point: 1625 ℃
The relative density: 6.017
Solubility soluble in sulfuric acid, hydrochloric acid and hydrofluoric acid, not soluble in hot dilute nitric acid, water and alkali

Barium titanate ceramics is one of the most widely used and thoroughly studied ferroelectric materials. Barium titanate is the first hydrogen free ferroelectric oxide, due to its excellent properties, good chemical and thermal stability. Barium titanate has excellent properties such as high dielectric constant and low dielectric loss, and is widely used in multi-layer ceramic capacitors, thermistors, photoelectric devices and other electronic components. It is one of the most widely used ceramic materials in the electronics industry.

1 the spontaneous polarization of barium titanate crystal
Barium titanate is a typical ferroelectric, so mention barium titanate, it must be mentioned the spontaneous polarization. Dielectric electric polarization process, in general, there are three (way), namely the electronic displacement polarization inherent electric moment, ion displacement polarization and turning-direction polarization. For barium titanate, after strictly calculated physicist, spontaneous polarization of batio3 contribution mainly comes from the Ti4 + ion displacement polarization and oxygen octahedral one of O2 - electronic displacement polarization.
2 the ferroelectric domain of barium titanate crystal
Barium titanate crystal is composed of a myriad of barium titanate crystal cell. When cubic barium titanate crystal cooling to the Curie point Tc, will begin to produce spontaneous polarization, and simultaneously cubic square phase shift. In the event of a spontaneous polarization, one part of each other near the cell through the cubic unit cell of a crystallographic axis to produce spontaneous polarization, and the other part of each other near the cell may be along the cubic unit cell of another major axis to produce spontaneous polarization. Such as barium titanate into four phase, crystal along different directions in the spontaneous polarization of small cell unit, we call it electric domain. That is to say, by lowering the temperature, crystal from shun electrical phase into a ferroelectric phase, due to the spontaneous polarization, surface electrostatic interaction, generate electricity domain structure. Electric domain type, the orientation of the domain wall, besides is mainly decided by the structure of the crystal symmetry, but also satisfy the following two conditions: (1) lattice deformation continuity: electric domain formed as a result, makes the domain wall and cut crystal produced by the two on the surface of the crystal lattice and match in a row. (2) the continuity of spontaneous polarization component: two adjacent domain on the spontaneous polarization in vertical direction Yu Chou wall of equal weight. Therefore, in sifang barium titanate crystal, spontaneous polarization direction of the adjacent electric domain cut only at 180 ° or 90 °, which is only 180 ° domain and 90 ° domain.
3 the dielectric properties of barium titanate
Here main refers to the dielectric properties of barium titanate dielectric properties of barium titanate ceramics. Dielectric properties of barium titanate ceramics are basically similar to single crystal of batio3. But since ceramic is polycrystalline structure, grain size and grain boundary. Grain size and orientation, glass phase in the grain boundary and the presence of impurities, are directly affect the dielectric properties, make its and single crystal is different.