Semiconductor - Order
1885 German mineralologies Weissa found a new ore-Freibao ore based on sulfide silver, ie, silver sulfide锗 矿 (4AG2S.GES2). In 1886, German Chemist Wenkele (C.A.Winkler) analyzed this new mineral, eight full analysis results were about 7%, so he concluded that the ore must have an unknown new element. He believes that this new element must be arsenic, bismuth, and tin three, which belongs to a group, so he melting minerals with sodium carbonate and sulfur, then dissolved in water, filtered, and a large amount of hydrochloric acid was added to the solution. White precipitation, the reduction of this precipitate was dried in the hydrogen stream, and the new element was obtained. In order to commemorate his motherland German, Wenke is named germanium, ie "锗", from Germany, Latin name "Germania".
Semiconductor - Characteristics
The position of germanium in the periodic table is exactly between metal and non-metals. Although germanium belongs to metal, it has many properties similar to non-metallic, called "semi-metal" in chemistry. In terms of their conductive capacity, it is better than general non-metallic, infer to general metal, so it is called "semiconductor" in physics. The content of the germanium in the crust is 1 million, and it is not a thinness. Then, 锗 is very dispersed, there is almost no concentrated germanium. Therefore, it is known as "thin tissue metal", and the main use of germanium is an important raw material for the semiconductor industry. To this end, the requirements for germanium purity are also high, and the purity of eight to nine 9 is usually required (~ 99.9999999%). Semiconductor germanium can be used to make various transistors, computers, etc .; due to temperature change, the resistance of germanium is immediately sensitive, so it can be used to manufacture "thermistor".
Preparation of germanium
generally recovered by by-products from the process of lead zinc smelting or combustion coal. The raw material was isolated from the main metal and enriched into a germanium concentrate, and purified from the main metal and was purified to be pure tetrachloride. Pure tetrachloride hydrolysis was obtained from high purity nerium dioxide, and after drying, hydrogen was reduced to metal germanium, and then the region was purified as high purity germanium, and finally made a single crystal germanium (see Dramatal single crystal).