Germanium

Germanium is a chemical element in Group 14 and Period 4 of the periodic table. It has the chemical symbol Ge and an atomic number of 32. As a metalloid, Germanium exhibits properties of both metals and nonmetals. It is found abundantly in the Earth's crust and is known for its potential immune-boosting effects in cancer patients. It is a lustrous, greyish-white element with a metallic appearance.

1.0Introduction 

Germanium belongs to the carbon family and shares similarities with the neighbouring elements silicon and tin. The periodic table follows silicon (Si) and is positioned just above tin (Sn) in Group 14. Although Dmitri Mendeleev predicted Germanium's existence and properties—calling it "ekasilicon" based on gaps in his periodic table—the element was not discovered until 1886 by the German chemist Clemens Winkler.

Germanium is widely used in transistors today, but its most significant applications are in fibre-optic systems and infrared optics.

2.0Physical properties of Germanium

3.0Chemical properties of Germanium

• Reacts with oxygen at 250 °C, forming germanium dioxide (GeO₂)
• Unreactive with dilute acids and bases
• Reacts slowly with concentrated hot sulfuric acid (H₂SO₄) and nitric acid (HNO₃)
• Reacts violently with molten bases
• Expands upon freezing, similar to water

Reaction with Chlorine:

• Ge + 2Cl₂ → GeCl₄ (Germanium chloride)

Reaction with Bromine:

• Ge + 2Br₂ → GeBr₄ (Germanium bromide)

4.0Production of Germanium

Occurrence: Germanium is found in the Earth’s crust at approximately 1.6 ppm. It is primarily found in minerals such as argyrodite, briartite, germanite, renierite, and sphalerite, with sphalerite being the primary source.

Extraction Process:

1. Ore Processing: Germanium is mainly produced as a byproduct of zinc ore processing, though it can also be obtained from copper and lead ores.
2. Roasting: The ore (e.g., sphalerite) is heated in air, converting it to germanium dioxide (GeO₂) through roasting.

Reaction: GeS₂ + 3O₂ → GeO₂ + 2SO₂

3. Reduction: The germanium dioxide (GeO₂) is reduced to elemental germanium by either carbon or hydrogen, depending on its intended use.
4. Reduction with hydrogen (for the semiconductor industry):

GeO₂ + 2H₂ → Ge + 2H₂O

5. Reduction with carbon (for steel industry):

GeO₂ + C → Ge + CO₂

5.0Uses of Germanium

Germanium has versatile applications due to its properties, like semiconductor behaviour and the high refractive index of its oxide. Below are its key uses:

1. Electronics:

• Used in transistors, electronic chips, and fluorescent lamps due to its semiconductor properties.
• Essential in the manufacture of solar cells and panels.

2. Optics:

• Germanium oxide is used in wide-angle camera lenses, optical fibres, and microscopy.
• Infrared optical material for windows, thermal imaging cameras, and night vision instruments.
• It is extensively used in military devices like fire-fighting and night-vision instruments.

3. Catalysis:

• Acts as a catalyst in polymerisation reactions.
• Used in gas chromatography columns as a substitute for silica.

4. Materials:

• Incorporated in alloys and fluorescent lamps.
• Germanium is applied to refining metals in metallurgy.

5. Healthcare:

• They are applied in the treatment of lung cancer and leukaemia.
• Used in oncological therapy, particularly for lung and blood cancer.

6. Space & Solar Technology:

• Employed in gallium arsenide solar cells and multijunction photovoltaic cells.
• Utilised in space applications due to its properties in solar technology.

7. Miscellaneous:

• Used in rewritable DVDs.
• Plays a role in manufacturing infrared spectrophotometers, microscopes, and cameras.

6.0Health Effects of Germanium

• Non-Essential Element: Germanium is not essential for plants or animals and has minimal environmental impact due to its trace presence in nature.
• Health Supplements: Some germanium supplements are used to treat diseases, claiming benefits like improving oxygen supply, boosting the immune system, and neutralising harmful free radicals. However, there is no solid scientific evidence to support these health claims.
• Potential Side Effects: Germanium supplements can cause side effects, such as muscle weakness, anaemia, and kidney damage. Research suggests that these supplements might be more harmful than beneficial.
• FDA Warning: The US FDA has warned against using inorganic germanium supplements due to potential health hazards.
• Cancer Research: Research on spirogermanium, a germanium derivative, initially showed some potential in targeting cancer cells. However, due to its harmful effects, the research was discontinued.