|
Atomic Number: |
32 |
Melting Point: | 938.25 ºC | |
Atomic Symbol: | Ge | Boiling Point: | 2833 ºC | ||
Atomic Weight: | 72.59 amu | Density: | 5323
kg/m 3 |
||
Atomic Radius: |
122.5 pm |
Oxidation States: | 4, 2 | ||
Covalent Radius: | 122 pm | Electron Configuration: | [Ar]4s23d104p2 | ||
van der Waals Radius: |
-- |
State of Matter: | solid |
(Latin Germania: Germany) Mendeleev predicted the existence of Germanium in 1871 as ekasilicon, and the element was discovered by Winkler in 1886.
The element is a gray-white metalloid. In pure state, the element is crystalline and brittle, retaining its luster in air at room temperature. It is a very important semiconductor. Zone-refining techniques have led to production of crystalline germanium for semiconductor use with an impurity of only one part in 1010.
The metal is found in argyrodite, a sulfide of germanium and silver; germanite, which contains 8 percent of the element; zinc ores, coal, and other minerals.
The element is commercially obtained from the dusts of smelters processing zinc ores, as well as recovered from combustion by-products of certain coals. A large reserve of the elements for future uses in insured in coal sources.
Germanium can be separated from other metals by fractional distillation of its volatile tetrachloride. The techniques permit the production of germanium of ultra-high purity.
The development of the germanium transistor opened the door to countless applications of solid-state electronics. Unlike most semiconductors, germanium has a small band gap, allowing it to efficiently respond to infrared light. It is therefore used in infrared spectroscopes and other optical equipment which require extremely sensitive infrared detectors. From 1950 through the early 1970s, this area provided an increasing market for germanium, but then high purity silicon began replacing germanium in transistors, diodes, and rectifiers. Germanium transistors are still used in electric guitar amplifiers by musicians who wish to reproduce the distinctive character of amplifiers from the early Rock and roll era. The demand for germanium in fiber optics communication networks, infrared night vision systems, and polymerization catalysts increased dramatically. These end uses represented 85% of worldwide germanium consumption for 2000.
Germanium is also finding many other applications including use as an alloying agent, as a phosphor in fluorescent lamps, and as a catalyst.
Germanium and germanium oxide are transparent to the infrared and are used in infrared spectroscopes and other optical equipment, including extremely sensitive infrared detectors. The high index of refraction and dispersion properties of its oxide's have made germanium useful as a component of wide-angle camera lenses and microscope objectives.
The field of organo-germanium chemistry is becoming increasingly important. Certain germanium compounds have a low mammalian toxicity, but a marked activity against certain bacteria, which makes them useful as chemotherapeutic agents.
Germanium has a total of twenty-five isotopes of which only five are stable.
As a solid, this product does not present special health hazards. Conditions and work practices which generate dust or fumes should be avoided or controlled.