Jul 15 2013
Topics Covered
Introduction
Chemical Properties
Physical Properties
Mechanical Properties
Thermal Properties
Applications
Introduction
Germanium is a chemical element with Ge as its symbol. It belongs to group 14 of the periodic table and its atomic number is 32.
Germanium was first located in a rare mineral called argyrodite. However, today it is primarily obtained from the smelting of zinc ores and as a byproduct of burning certain types of coal.
Germanium has a diamond-like crystalline structure which is hard, lustrous, gray-white, and brittle. It is known to be stable in air and water, and is not affected by alkalis and acids with the exception of nitric acid.
Chemical Properties
The chemical properties of germanium are provided in the table below.
|
Chemical Data |
|
CAS number |
7440-56-4 |
|
Thermal neutron cross section |
2.5 barns/atom |
|
Ionic radius |
0.530 Å |
|
Electronegativity |
2.01 |
|
X-ray absorption edge |
1.116 Å |
Physical Properties
The following table discusses the physical properties of germanium.
|
Properties |
Metric |
Imperial |
|
Density |
5.323 g/cm3 |
0.1923 lb/in3 |
|
Melting point |
937°C |
1719°F |
|
Boiling point |
2830 °C |
2830°F |
Mechanical Properties
The mechanical properties of germanium are tabulated below.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
135-150 MPa |
19.5801-21.7557 ksi |
|
Poisson’s ratio |
0.3 |
0.3 |
|
Modulus of elasticity |
130 GPa |
18900 ksi |
|
Shear modulus |
50 GPa |
7250 ksi |
Thermal Properties
The thermal properties of germanium are tabulated below.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (@20-°C/68°F) |
6.10 µm/m°C |
3.39 µin/in°F |
|
Thermal conductivity |
64 W/mK |
444 BTU in/hr.ft².°F |
Applications
Germanium is largely used in the semiconductor industry. The following are the other application areas of germanium:
-
To manufacture alloys
-
Electronics and solar electric components
-
As a phosphor in fluorescent lamps
Germanium and germanium oxide are used in infrared optical instruments and infrared detectors. Germanium compounds are being researched for killing some types of bacteria and for use in chemotherapy.