Germanium

Germanium is a chemical element with the symbol Ge and atomic number 32. It looks grayish-white and is hard but brittle, like silicon. Germanium is a special kind of element called a metalloid, meaning it has properties of both metals and nonmetals.

Germanium was predicted in 1869 by Dmitri Mendeleev when he made his famous periodic table. It was found in 1886 by Clemens Winkler in a mineral called argyrodite. Winkler named it after his home country, Germany.

Today, germanium is important for making electronics. It is used in transistors and many modern devices like fibre-optic systems, infrared optics, solar cell applications, and light-emitting diodes (LEDs). It is also used in chemical reactions and in making very tiny wires called nanowires.

History

In 1869, the scientist Dmitri Mendeleev guessed that some elements had not yet been found. He said one would fit between silicon and tin, and he called it ekasilicon.

In 1885, a new mineral was found near Freiberg, Saxony. A chemist named Clemens Winkler studied it and found a new element in 1886. He named it germanium after Germany, his home country. This new element matched what Mendeleev had guessed.

Winkler made new compounds with germanium and shared his findings in 1887. Germanium was later found to be useful in electronics, especially after 1945. It was used in early radar devices and in the first transistor in 1948. Even though silicon later became more common, germanium is still used in some special tools today.

Characteristics

Germanium is a brittle, silvery-white material that acts like a semiconductor. It has a shiny, metallic look and forms a special type called α-germanium. This type shares the same crystal shape as silicon and diamond. Under very high pressure, germanium changes into another form called β-germanium, similar to the metal tin.

Germanium is useful because it can control electricity. This makes it important for tiny electronic parts. It can also stretch into long, thin lines that sometimes cause problems in older electronic devices.

Chemistry

Germanium slowly changes when exposed to air, forming a compound called GeO₂. It does not dissolve in weak acids or alkalis but can dissolve in strong acids. It also reacts strongly with hot molten alkalis to make germanates.

Germanium mostly exists in a form called +4, but it can also be found in +2 and other rare forms. It forms different compounds with oxygen, such as germanium dioxide (GeO₂) and germanium monoxide (GeO). These compounds have special properties.

Germanium also makes compounds with other elements, such as sulfur and chlorine. For example, it forms germanium disulfide (GeS₂) and germanium tetrachloride (GeCl₄). These compounds can be used to make other germanium-based materials.

Organogermanium compounds, which include germanium combined with carbon, were first made in 1887. These compounds can be used in electronics.

Using special chemicals, germanium can form bonds with oxygen, creating compounds known as germanones.

Isotopes

Main article: Isotopes of germanium

Germanium occurs naturally in five different forms, called isotopes. The most common is ⁷⁴Ge. Another isotope, ⁷⁶Ge, is very slightly radioactive and changes over a very long time.

Besides these natural isotopes, scientists have made over 27 other radioactive isotopes of germanium in labs. The most stable of these is ⁶⁸Ge, which changes over about 271 days.

Occurrence

See also: Category:Germanium minerals

Germanium is created in stars through a process called the s-process. It can be found in some of the farthest stars and in the atmosphere of Jupiter.

On Earth, germanium is quite rare, found in very small amounts in the crust. It is mainly found in a few minerals such as argyrodite, briartite, germanite, renierite, and sphalerite. These minerals are rarely found in amounts large enough to mine. However, some coal deposits, especially near Xilinhaote in Inner Mongolia, contain high amounts of germanium.

Production

In 2011, about 118 tonnes of germanium were made around the world. Most came from China, with smaller amounts from Russia and the United States. Germanium is often found when mining zinc. It can also be found in silver, lead, and copper ores, and in the ash from coal-powered plants.

To get germanium from its ores, the materials are heated to turn them into oxides. These oxides are treated with acids and chemicals to separate out the germanium. The germanium can then be used to make glass and materials for electronics. Different methods are used depending on whether the germanium is for making steel or for purer uses like semiconductors.

Applications

Germanium has many important uses. One-fourth is used to make fiber optic wires, and some is used to see in infrared light. It also helps make plastics clearer and stronger, and is used in electronics and solar power.

Germanium is good for special glass that bends light well. This makes it great for cameras, microscopes, and tiny wires that carry internet signals. It can also be made clear to see heat, which helps with night-vision goggles and cameras that find hot spots.

In electronics, germanium mixes with silicon to make fast chips. It is also used in solar panels for space, like on robots that explore Mars. Some old music gear used germanium to make special sounds, and scientists are studying it for tiny sensors inside the body.

Germanium and health

Germanium is not known to help plants or animals stay healthy. It is usually found only in very small amounts in rocks and other materials. The amounts used in products are so small that they are not likely to be eaten. Because of this, germanium does not usually affect health or the environment in a harmful way.

Some people have sold germanium supplements to treat serious illnesses, but there is no proof that they work. In fact, some research shows that these supplements can be harmful. Certain forms of germanium used in supplements have been linked to health problems in people who used them for a long time.

Precautions for chemically reactive germanium compounds

While germanium itself is safe to use, some man-made germanium compounds can be very harmful if you come into contact with them. For example, certain germanium liquids and gases can irritate the eyes, skin, lungs, and throat.