Gallium (III) oxide
Crystal structure | ||||||||||||||||
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__ Ga 3+ __ O 2− | ||||||||||||||||
General | ||||||||||||||||
Surname | Gallium (III) oxide | |||||||||||||||
other names |
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Ratio formula | Ga 2 O 3 | |||||||||||||||
Brief description |
white, crystalline solid |
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properties | ||||||||||||||||
Molar mass | 187.5 g mol −1 | |||||||||||||||
Physical state |
firmly |
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density |
5.88 g cm −3 |
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Melting point |
1740 ° C |
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solubility |
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safety instructions | ||||||||||||||||
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . |
Gallium (III) oxide is a chemical compound of gallium and is one of the oxides . The colorless, crystalline solid occurs in five modifications .
Extraction and presentation
Gallium (III) oxide can be obtained by dehydrating gallium hydroxide at 500 ° C.
An alternative is the decomposition of gallium nitrate at 200 ° C. The two ways of representation lead to different modifications, which are converted into the most stable β-modification at higher temperatures.
properties
The modifications of gallium (III) oxide are designated with the Greek letters α to ε. The most stable is the monoclinic β modification. If gallium hydroxide is dehydrated, the γ-modification forms first, the structure of which is a spinel structure with gallium defects. With prolonged heating, this changes into the α-Ga 2 O 3 modification with a corundum structure and finally into β-Ga 2 O 3 .
In the reaction pathway via gallium nitrate, the bixbyite- like δ-modification is initially formed , which also converts to β-Ga 2 O 3 when heated more strongly via the orthorhombic ε phase .
Several gallium oxide modifications show photocatalytic activity in the decomposition of aromatic compounds such as benzene or toluene . It is higher than that of the frequently used titanium (IV) oxide .
use
Gallium (III) oxide is the starting material for the production of gadolinium gallium garnet for magnetic bubble storage .
Individual evidence
- ↑ a b digallium trioxide at webelements.com .
- ↑ a b c d e f data sheet Gallium (III) oxide, Puratronic®, 99.999% (metals basis) from AlfaAesar, accessed on December 23, 2019 ( PDF )(JavaScript required) .
- ^ A b c d A. F. Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 , p. 1196.
- ^ A b S. Yoshioka, H. Hayashi, A. Kuwabara, F. Oba, K. Matsunaga, I Tanaka: Structures and energetics of Ga 2 O 3 polymorphs. In: J. Phys .: Condens. Matter . 2007, 19, pp. 346211-22, doi : 10.1088 / 0953-8984 / 19/34/346211 .
- ↑ Yidong Hou, Ling Wu, Xinchen Wang, Zhengxin Ding, Zhaohui Li, Xianzhi Fu: Photocatalytic performance of α-, β-, and γ-Ga 2 O 3 for the destruction of volatile aromatic pollutants in air. In: Journal of Catalysis. 2007, 250, 1, pp. 12-18, doi : 10.1016 / j.jcat.2007.05.012 .
- ↑ Entry on gallium compounds. In: Römpp Online . Georg Thieme Verlag, accessed on June 13, 2014.