Barium orthotitanate is the

inorganic compound In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemist ...

with the

chemical formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, ...

Ba₂TiO₄. It is a colourless solid that is of interest because of its relationship to

barium titanate Barium titanate (BTO) is an inorganic compound with chemical formula BaTiO3. Barium titanate appears white as a powder and is transparent when prepared as large crystals. It is a Ferroelectricity, ferroelectric, Pyroelectricity, pyroelectric, and ...

, a useful

electroceramic Electroceramics is a class of ceramic materials used primarily for their electrical properties. While ceramics have traditionally been admired and used for their mechanical, thermal and chemical stability, their unique electrical, optical and magn ...

Structure

The solid has two known phases: a low-temperature (β) phase with ''P''2₁/''n'' symmetry and a high-temperature (α′) phase with ''P''2₁''nb'' symmetry. The structure of Ba₂TiO₄ is unusual among the

titanate In chemistry, titanate usually refers to inorganic compounds composed of titanium oxides. Together with niobate, titanate salts form the Perovskite group. In some cases, the term is used more generally for any titanium-containing anion, e.g. iC ...

s because its titanium atoms sit in a four-oxygen tetrahedron rather than a six-oxygen octahedron.

Production

It forms as white crystals from a melt of BaCl₂, BaCO₃ and TiO₂ or from just

sintering Clinker nodules produced by sintering Sintering or frittage is the process of compacting and forming a solid mass of material by pressure or heat without melting it to the point of liquefaction. Sintering happens as part of a manufacturing ...

BaCO₃ and TiO₂. Another method of preparation is heating pellets of Ba(OH)₂ and TiO₂. Additionally, there are polymer

precursor Precursor or Precursors may refer to: *Precursor (religion), a forerunner, predecessor ** The Precursor, John the Baptist Science and technology * Precursor (bird), a hypothesized genus of fossil birds that was composed of fossilized parts of unr ...

, sol-gel and reverse micellar routes to Ba₂TiO₄ synthesis. Ba₂TiO₄ has also been successfully grown as a

thin film A thin film is a layer of material ranging from fractions of a nanometer (monolayer) to several micrometers in thickness. The controlled synthesis of materials as thin films (a process referred to as deposition) is a fundamental step in many ap ...

with

chemical vapor deposition Chemical vapor deposition (CVD) is a vacuum deposition method used to produce high quality, and high-performance, solid materials. The process is often used in the semiconductor industry to produce thin films. In typical CVD, the wafer (substra ...

Properties

* Room temperature

entropy Entropy is a scientific concept, as well as a measurable physical property, that is most commonly associated with a state of disorder, randomness, or uncertainty. The term and the concept are used in diverse fields, from classical thermodynam ...

- 47.0 cal/deg. mol *

Dielectric constant The relative permittivity (in older texts, dielectric constant) is the permittivity of a material expressed as a ratio with the electric permittivity of a vacuum. A dielectric is an insulating material, and the dielectric constant of an insulat ...

- 20 (at 100 kHz) * It is

hygroscopic Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption or adsorption from the surrounding environment, which is usually at normal or room temperature. If water molecules become suspended among the substance ...

and decomposes with swelling in moist air. Barium orthotitanate can remove up to 99.9% of from a high-temperature gas stream by the reaction: : + → +

References

{{Titanium compounds Titanates Barium compounds