germanium

Germanium the Element

Germanium as an element was identified in 1886 by a German chemist Clemens Winkler. The existence of an element with Germanium's atomic structure was actually predicted by the Russian chemist Mendeleev, who left a space in his periodic table for an element which he named 'ekasilicon'. Winkler isolated this element during an analysis of the ore argyrodite, a silver mineral, from the Himmelsfurst mine, St. Michaelis near Freiburg in Saxony and named it Germanium after his homeland. Germanium belongs to family four of the periodic table, along with carbon, silicon, tin and lead, and is usually classified as a semi-metal, or said to have semiconductor properties.

Germanium is not that rare in the universe, with estimates ranging from 10-55 parts per million (ppm) (92). On the earth's crust its concentration is approximately 6 ppm therefore being more abundant than gold, silver, cadmium, bismuth, antimony and mercury, and in the same range as molybdenum, arsenic, tin, boron and beryllium. Germanium rarely forms its own mineral deposits. In most cases, Germanium is found in small (ppm) levels in the sulphidic ores of lead, zinc and copper, although occasionally levels of 100 ppm have been found in deep thermal deposits of zinc. Germanium is highly concentrated in some coals, about 500 ppm.

The highest reservoirs, worldwide, of Germanium are found in Tsumeb (formerly German South West Africa) and Kipushi (Zaire), with concentrations reaching 1000 ppm.

$Germanium Atomic Number: 32 Atomic Symbol: Ge Atomic Weight: 72.59 Electron Configuration: 2-8-18-4 Shells: 2,8,18,4 Filling Orbital: 5s1 Melting Point: 38.89oC Boiling Point: 688oC Uses: catalyst, photocells, vaccum tubes Group Period Index History (Latin Germania, Germany) Mendeleev predicted the existence of Germanium in 1871 as ekasilicon, and the element was discovered by Clemens Winkler of Germany in 1886. Sources The metal is found in • argyrodite, a sulfide of germanium and silver; • germanite, which containes 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. Properties • The element is a gray-white metalloid. In its pure state, the element is crystalline and brittle, retaining its luster in air at room temperature. • It is a very important semiconductor material. • Zone-refining techniques have led to production of crystalline germanium for semiconductor use with an impurity of only one part in 1010. Uses When germanium is doped with arsenic, gallium, or other elements, it is used as a transistor element in thousands of electronic applications. The most common use of germanium is as a semiconductor. 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 organogermanium 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. Costs The cost of germanium is about $3/g.$ shapeimage_2_link_0