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Barium oxide, also known as baria, is a white hygroscopic non-flammable compound with the formula BaO. It has a cubic structure and is used in cathode-ray tubes, crown glass, and catalysts. It is harmful to human skin and if swallowed in large quantity causes irritation. Excessive quantities of barium oxide may lead to death.
Barium is a chemical element; it has symbol Ba and atomic number 56. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal . Because of its high chemical reactivity , barium is never found in nature as a free element.
2 Structure and properties. 3 Thermodynamic properties. 4 Spectral data. ... This page provides supplementary chemical data on barium oxide. Material Safety Data Sheet
Barium hydroxide can be prepared by dissolving barium oxide (BaO) in water: BaO + H 2 O → Ba(OH) 2. It crystallises as the octahydrate, which converts to the monohydrate upon heating in air. At 100 °C in a vacuum, the monohydrate will yield BaO and water. [3] The monohydrate adopts a layered structure (see picture above).
Although the perovskite structure is named after CaTiO 3, this mineral has a non-cubic structure. SrTiO 3 and CaRbF 3 are examples of cubic perovskites. Barium titanate is an example of a perovskite which can take on the rhombohedral (space group R3m, no. 160), orthorhombic, tetragonal and cubic forms depending on temperature. [7]
Barium peroxide arises by the reversible reaction of O 2 with barium oxide. The peroxide forms around 500 °C and oxygen is released above 820 °C. [1] 2 BaO + O 2 ⇌ 2 BaO 2. This reaction is the basis for the now-obsolete Brin process for separating oxygen from the atmosphere. Other oxides, e.g. Na 2 O and SrO, behave similarly. [4]
Yttrium barium copper oxide (YBCO) is a family of crystalline chemical compounds that display high-temperature superconductivity; it includes the first material ever discovered to become superconducting above the boiling point of liquid nitrogen [77 K (−196.2 °C; −321.1 °F)] at about 93 K (−180.2 °C; −292.3 °F).
Structure of cubic BaTiO 3. The red spheres are oxide centres, blue are Ti 4+ cations, and the green spheres are Ba 2+. The solid exists in one of four polymorphs depending on temperature. From high to low temperature, these crystal symmetries of the four polymorphs are cubic, tetragonal, orthorhombic and rhombohedral crystal structure.