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32. GermaniumName: Germanium
The element is a gray-white metalloid, and in its pure state is crystalline and brittle, retaining its lustre 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 10-10. Certain germanium compounds have a low mammalian toxicity, but a clear activity against certain bacteria, which makes them of interest as chemotherapeutic agents. In 1871 germanium (Latin Germania for Germany) was one of the elements that Dmitri Mendeleev predicted to exist as a missing analogue of the silicon group (Mendeleev called it "ekasilicon"). The existence of this element was proven by Clemens Winkler in 1886. This discovery was an important confirmation of Mendeleev's idea of element periodicity. The development of the germanium transistor opened the door to countless applications of solid-state electronics. 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. Silicon has superior electrical properties, but requires much higher purity samples—a purity which could not be commercially achieved in the early days. Meanwhile, 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. Quick links
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