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Beryllium oxide

Beryllium oxide
Other names Beryllia
CAS number 1304-56-9
Molecular formula BeO
Molar mass 25.01
Appearance white solid
Density 3.0 g/cm³ (solid)
Melting point

2530 °C

Boiling point

3900 °C

MSDS External MSDS
EU classification Highly toxic (T+)
Carc. Cat. 2
NFPA 704
R-phrases R49, R25, R26,
R36/37/38, R43, R48/23
S-phrases S53, S45
Flash point Non-flammable
Related Compounds
Other anions Beryllium telluride
Other cations Magnesium oxide
Calcium oxide
Supplementary data page
Structure and
n, εr, etc.
Phase behaviour
Solid, liquid, gas
Spectral data UV, IR, NMR, MS
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Beryllium oxide (BeO) is a white crystalline oxide. It is obtained from beryllium or beryllium compounds by ignition in the air. The sintered beryllium oxide (beryllia), which is very stable, has ceramic characteristics. It is similar to aluminium oxide (Al2O3), is highly fire resistant (melting point: 2570°C), and has polymorphism. Beryllium oxide was previously called glucina.

Beryllium oxide formed at high temperatures (>800°C) is inert but may be easily dissolved in hot aqueous ammonium bifluoride (NH4HF2) or a hot solution of concentrated sulfuric acid (H2SO4) and ammonium sulfate ((NH4)2SO4).

Unlike oxides formed by the other alkaline earth metals, beryllium oxide is amphoteric rather than basic.

Currently there are only two companies in the United States that manufacture Beryllium Oxide. they are American Beryllia Inc. of Haskell New Jersey, and Brush Ceramics of Tucson Arizona.


This complex is used for rocket engines, catalysts, semiconductors, moderators of atomic reactors, and neutron reflectors.

Beryllium oxide is used in many high-performance semiconductor parts for applications such as radio equipment because it has good thermal conductivity while also being a good electrical insulator. Some power semiconductor devices have used beryllium oxide ceramic to insulate the silicon chip from the metal mounting base of the package in order to achieve a lower value thermal resistance than for a similar construction made with aluminium oxide. It is also used as a structural ceramic for high-performance vacuum tubes, magnetrons, and gas lasers.


BeO is carcinogenic if the powder is ingested or inhaled and may cause chronic beryllium disease.


    This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Beryllium_oxide". A list of authors is available in Wikipedia.
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