Germanium

Atomic Number: 32

           Germanium is a gray-white metalloid, and an important semiconductor material.   

History

       

 Germanium is named for Germany, where Clemens Winkler discovered it in 1886 in a compound called argyrodite.  D. I. Mendeleev had first predicted its existence in 1871 because of a gap in the periodic table.  He made several hypotheses about the compound, from periodic trends, calling the element "ekasilicon."    Now, Germanium alloys are used to make transistors, computer chips, lasers, and many other things.  

 

 

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.

Click here for Germanium's vital statistics.

To see a picture of germanium atoms, click here.

Sources

Germanium is found in:

• argyrodite, a sulfide of germanium and silver ;
• germanite, which contains 8 percent of the element;
• zinc ores;
• coal; and
• other minerals.

Commercially, germanium is a result of smelters processing zinc ores, and can also be obtained as combustion by-products in certain coals.  

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.

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." (http://pearl1.lanl.gov/periodic/elements/32.html).

Germanium is also useful in making lasers.  Click on the picture below to learn more about Erik Brundermann's research with Germanium lasers.

Costs

The cost of germanium is about $1,150/kg.

Home Vital Statistics  Bibliography

This page was created by Verity Decker for her Chemistry class at Pomona College.

Visit the Pomona College Website!

Any questions or comments? E-mail her!