germanium

Germanium is a grayish-white, metallic element with electrical characteristics between those of a metal and an insulator, making it a semiconductor. It is commercially available as a tetrachloride, a high-purity oxide, and in the form of zone-refined metal ingots, single-crystal bars, castings, doped semiconductors, optical materials, optical blanks, and other specialty products. Germanium is used principally in fiber optics, in infrared optics, and in polymerization catalysts. Its excellent mechanical, optical, and electrical properties, as well as its moderate cost and availability in large sizes make it attractive in many aerospace applications. In 1997, the estimated germanium content of imports was approximately 24,000 kg, about 14％ less than in 1996. Russia, Belgium, China, the Ukraine, and the United Kingdom, in descending order of shipments, accounted for approximately 91％ of U.S. germanium imports for 1997. (See table 1.) Imports directly attributable to China and countries of the former Soviet Union amounted to about 60％ of the total. Trade reliance on large shipments from these countries is a fairly new pattern, beginning in 1993.