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About Germanium

Germanium Bohr

When Mendeleev published his first Periodic Table of the Elements in 1869, he included several as-yet undiscovered elements. He gave each a temporary name and predicted its properties based on the surrounding elements. One of these was named ekasilicon, and Mendeleev almost perfectly predicted the properties of the actual element, which was discovered by Clemens Winkler in 1886 and named after his native Germany: thus, germanium.

Germanium is a semiconducting metalloid with properties similar to silicon, and its use in electronic devices actually pre-dated the use of the more famous element. The first transistors were produced from germanium in Bell labs in 1947. Ultimately, the technologies available for use with silicon and the abundance of silicon led to many more semiconductor applications using silicon, including standard computer chips, and for many years germanium played a limited role in semiconductor devices. However, today new technologies are again making germanium a key material for electronics applications. Germanium is preferable to silicon in some types of photovoltaic cells used to harvest solar energy, and is used as a key substrate material in production of high-brightness LEDs for flashlights, automobile tail lights, cameras, traffic signals, and display screens. As an LED component, germanium is sometimes preferable to the alternative, gallium arsenide, as it breaks less frequently and poses fewer disposal issues. Additionally, microchip designs using germanium-on-insulator or silicon-germanium technology are seeing increased use.

Another key use of germanium comes from the favorable optical properties of it and some of its compounds. Germanium oxide has a high index of refraction and low optical dispersion, making it appropriate for use in wide-angle lenses and some microscopes. Germanium oxide also imparts some of these properties when used as a dopant in silica glass, and is used as such in the core of optical fibers. An additional useful optical property is that germanium glass is transparent to infrared radiation. It is therefore used in thermal imaging cameras, night vision systems, and sensitive infrared detectors. Another use of germanium in optical systems is in the material germanium-antimony-tellurium, or GeSbTe, a phase change material used in rewritable optical disks (CD-RW, DVD-RW) and other phase change memory devices.

In addition to its electronic and optical applications, germanium also finds uses in a few other key areas. Germanium oxide is used as a catalyst in the making of many plastics. When germanium is added in small amounts to sterling silver, it reduces firescale and tarnish, and makes the final metal harder. Contrary to past beliefs, germanium has not been shown to have any medical function and is considered potentially hazardous if consumed; nonetheless some nutritional supplements contain the element.

Though germanium is not particularly rare, it is not contained in any mineral in large enough percentages to be worth mining for germanium specifically. Instead, germanium is derived from concentrates produced as byproducts of mining for other metals, particularly zinc, and is additionally recovered from the fly ash of some coal power plants.

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Germanium is a very important semiconductor and is also finding many other applications including use as an alloying agent, as a phosphor in High Purity (99.999%) Germanium Oxide (GeO2) Powderfluorescent lamps, and as a catalyst. Germanium and germanium oxide are transparent to the infrared and are used in infrared spectroscopes High Purity (99.99%) Germanium (Ge) Sputtering Targetand other optical equipment, including extremely sensitive infrared detectors. The high refractive index and dispersion properties of its oxides have made germanium useful as a component of wide-angle camera lenses and microscope objectives. Elemental or metallic forms of Germanium include pellets, rod, wire and granules for evaporation source material purposes. Germanium oxide is available in forms including powders and dense pellets for such uses as optical coating and thin film applications. Oxides tend to be insoluble. Fluorides are another insoluble form for uses in which oxygen is undesirable such as metallurgy, chemical and physical vapor deposition and in some optical coatings. Germanium is also available in soluble forms including chlorides, nitrates and acetates. These compounds can be manufactured as solutions at specified stoichiometries.

Germanium Properties

Germanium (Ge) atomic and molecular weight, atomic number and elemental symbolGermanium is a Block P, Group 14, Period 4 element. The number of electrons in each of germanium's shells is 2, 8, 18, 4 and its electron configuration is [Ar] 3d10 4s2 4p2. Germanium Bohr ModelThe germanium atom has a radius of and its Van der Waals radius is In its elemental form, CAS 7440-56-4, germanium is a brittle grayish white semi-metallic element. Germanium is too reactive to be found naturally on Earth in its native state. It is commercially obtained from zinc High Purity (99.999%) Germanium (Ge) Metal ores and certain coals. It is also found in argyrodite and germanite. Germanium was first discovered by Clemens Winkler in 1886. The name Germanium originates from the Latin word "Germania" meaning "Germany".

Symbol: Ge
Atomic Number: 32
Atomic Weight: 72.63
Element Category: metalloid
Group, Period, Block: 14, 4, p
Color: grayish white
Other Names: N/A
Melting Point: 938.25 °C, 1720.85 °F, 1211.40 K
Boiling Point: 2833 °C, 5131 °F, 3106 K
Density: 5.323 g·cm3
Liquid Density @ Melting Point: 5.60 g·cm3
Density @ 20°C: 5.323 g/cm3
Density of Solid: 5323 kg·m3
Specific Heat: N/A
Superconductivity Temperature: N/A
Triple Point: N/A
Critical Point: N/A
Heat of Fusion (kJ·mol-1): 34.7
Heat of Vaporization (kJ·mol-1): 327.6
Heat of Atomization (kJ·mol-1): 373.8
Thermal Conductivity: 60.2 W·m-1·K-1
Thermal Expansion: 6.0 µm/(m·K)
Electrical Resistivity: (20 °C) 1 µ·m
Tensile Strength: N/A
Molar Heat Capacity: 23.222 J·mol-1·K-1
Young's Modulus: 103 GPa
Shear Modulus: 41 GPa
Bulk Modulus: 75 GPa
Poisson Ratio: 0.26
Mohs Hardness: 6
Vickers Hardness: N/A
Brinell Hardness: N/A
Speed of Sound: (20 °C) 5400 m·s-1
Pauling Electronegativity: 2.01
Sanderson Electronegativity: 2.62
Allred Rochow Electronegativity: 2.02
Mulliken-Jaffe Electronegativity: 2.33 (sp3 orbital)
Allen Electronegativity: 1.994
Pauling Electropositivity: 1.99
Reflectivity (%): 54
Refractive Index: N/A
Electrons: 32
Protons: 32
Neutrons: 41
Electron Configuration: [Ar] 3d10 4s2 4p2
Atomic Radius: 122 pm
Atomic Radius,
non-bonded (Å):
Covalent Radius: 122 pm
Covalent Radius (Å): 1.2
Van der Waals Radius: 211 pm
Oxidation States: 4, 3, 2, 1, 0, -1, -2, -3, -4
Phase: Solid
Crystal Structure: diamond cubic
Magnetic Ordering: Diamagnetic[
Electron Affinity (kJ·mol-1) 118.966
1st Ionization Energy: 762.18 kJ·mol-1
2nd Ionization Energy: 1537.47 kJ·mol-1
3rd Ionization Energy: 3302.15 kJ·mol-1
CAS Number: 7440-56-4
EC Number: 231-164-3
MDL Number: MFCD00085310
Beilstein Number: N/A
SMILES Identifier: [Ge]
InChI Identifier: InChI=1S/Ge
PubChem CID: 6326954
ChemSpider ID: 4885606
Earth - Total: 7.6 ppm 
Mercury - Total: 1.24 ppm
Venus - Total: 8.4 ppm
Earth - Seawater (Oceans), ppb by weight: 0.06
Earth - Seawater (Oceans), ppb by atoms: 0.0051
Earth -  Crust (Crustal Rocks), ppb by weight: 1400
Earth -  Crust (Crustal Rocks), ppb by atoms: 390
Sun - Total, ppb by weight: 200
Sun - Total, ppb by atoms: 3
Stream, ppb by weight: N/A
Stream, ppb by atoms: N/A
Meterorite (Carbonaceous), ppb by weight: 21000
Meterorite (Carbonaceous), ppb by atoms: 4900
Typical Human Body, ppb by weight: N/A
Typical Human Body, ppb by atom: N/A
Universe, ppb by weight: 200
Universe, ppb by atom: 3
Discovered By: Clemens Winkler
Discovery Date: 1886
First Isolation: N/A

Health, Safety & Transportation Information for Germanium

Germanium is not toxic in its elemental form; however, safety data for Germanium metal, nanoparticles and its compounds can vary widely depending on the form. For potential hazard information, toxicity, and road, sea and air transportation limitations, such as DOT Hazard Class, DOT Number, EU Number, NFPA Health rating and RTECS Class, please see the specific Germanium material or compound referenced in the Products tab.

Safety Data
Signal Word Warning
Hazard Statements H315-H319-H335
Hazard Codes Xi
Risk Codes 36/37/38
Safety Precautions 26-36/39
RTECS Number LY5200000
Transport Information N/A
WGK Germany 3
Globally Harmonized System of
Classification and Labelling (GHS)
Exclamation Mark-Acute Toxicity
Review and Print SDS for Germanium Metal


Date Created: 05/15/2015
Date Revised: 05/15/2015


Product Name: Germanium Metal

Product Number: All applicable American Elements product codes, e.g. GE-E-05-I, GE-E-05-L, GE-E-05-P, GE-E-05-ST, GE-E-05-WSX

CAS #: 7440-56-4

Relevant identified uses of the substance: Scientific research and development

Supplier details:
American Elements
1093 Broxton Ave. Suite 2000
Los Angeles, CA 90024
Tel: +1 310-208-0551
Fax: +1 310-208-0351

Emergency telephone number:
Domestic, North America +1 800-424-9300
International +1 703-527-3887


Classification of the substance or mixture
Classification according to Regulation (EC) No 1272/2008
The substance is not classified as hazardous to health or the environment according to the CLP regulation.
Classification according to Directive 67/548/EEC or Directive 1999/45/EC
Not applicable
Information concerning particular hazards for human and environment:
No information known.
Hazards not otherwise classified
No information known.
Label elements
Labelling according to Regulation (EC) No 1272/2008
Not applicable
Hazard pictograms
Not applicable
Signal word
Not applicable
Hazard statements
Not applicable
WHMIS classification
Not controlled
Classification system
HMIS ratings (scale 0-4)
(Hazardous Materials Identification System)

Health (acute effects) = 0
Flammability = 0
Physical Hazard = 0
Other hazards
Results of PBT and vPvB assessment
Not applicable.
Not applicable.


Chemical characterization: Substances
CAS# Description:
7440-56-4 Germanium
Identification number(s):
EC number:


Description of first aid measures
General information
No special measures required.
After inhalation
Seek medical treatment in case of complaints.
After skin contact
Generally the product does not irritate the skin.
After eye contact
Rinse opened eye for several minutes under running water. If symptoms persist, consult a doctor.
After swallowing
If symptoms persist consult doctor.
Information for doctor
Most important symptoms and effects, both acute and delayed
No further relevant information available.
Indication of any immediate medical attention and special treatment needed
No further relevant information available.


Extinguishing media
Suitable extinguishing agents
Special powder for metal fires. Do not use water.
For safety reasons unsuitable extinguishing agents
Special hazards arising from the substance or mixture
If this product is involved in a fire, the following can be released:
Metal oxide fume
Advice for firefighters
Protective equipment:
No special measures required


Personal precautions, protective equipment and emergency procedures
Not required.
Environmental precautions:
Do not allow material to be released to the environment without proper governmental permits.
Do not allow product to reach sewage system or any water course.
Do not allow to penetrate the ground/soil.
Methods and material for containment and cleaning up:
Pick up mechanically.
Prevention of secondary hazards:
No special measures required.
Reference to other sections
See Section 7 for information on safe handling
See Section 8 for information on personal protection equipment.
See Section 13 for disposal information.


Precautions for safe handling
Keep container tightly sealed.
Store in cool, dry place in tightly closed containers.
Information about protection against explosions and fires:
No special measures required.
Conditions for safe storage, including any incompatibilities
Requirements to be met by storerooms and receptacles:
No special requirements.
Information about storage in one common storage facility:
Not required.
Further information about storage conditions:
Keep container tightly sealed.
Store in cool, dry conditions in well sealed containers.
Specific end use(s)
No further relevant information available.


Additional information about design of technical systems:
No further data; see section 7.
Control parameters
Components with limit values that require monitoring at the workplace:
The product does not contain any relevant quantities of materials with critical values
that have to be monitored at the workplace.
Additional information:
No data
Exposure controls
Personal protective equipment
General protective and hygienic measures
The usual precautionary measures for handling chemicals should be followed.
Maintain an ergonomically appropriate working environment.
Breathing equipment:
Not required.
Protection of hands:
Not required.
Penetration time of glove material (in minutes)
Not determined
Eye protection:
Safety glasses
Body protection:
Protective work clothing.


Information on basic physical and chemical properties
General Information
Form: Solid in various forms
Color: Silver-colored
Odor: Odorless
Odor threshold: Not determined.
pH-value: Not applicable.
Change in condition
Melting point/Melting range: 937.2 °C (1719 °F)
Boiling point/Boiling range: 2830 °C (5126 °F)
Sublimation temperature / start: Not determined
Flammability (solid, gaseous)
Not determined.
Ignition temperature: Not determined
Decomposition temperature: Not determined
Auto igniting: Not determined.
Danger of explosion: Not determined.
Explosion limits:
Lower: Not determined
Upper: Not determined
Vapor pressure at 20 °C (68 °F): 0 hPa
Density at 20 °C (68 °F): 5.32 g/cm³ (44.395 lbs/gal)
Relative density
Not determined.
Vapor density
Not applicable.
Evaporation rate
Not applicable.
Solubility in / Miscibility with Water: Insoluble
Partition coefficient (n-octanol/water): Not determined.
dynamic: Not applicable.
kinematic: Not applicable.
Other information
No further relevant information available.


No information known.
Chemical stability
Stable under recommended storage conditions.
Thermal decomposition / conditions to be avoided:
Decomposition will not occur if used and stored according to specifications.
Possibility of hazardous reactions
No dangerous reactions known
Conditions to avoid
No further relevant information available.
Incompatible materials:
No information known.
Hazardous decomposition products:
Metal oxide fume


Information on toxicological effects
Acute toxicity:
The Registry of Toxic Effects of Chemical Substances (RTECS) contains acute toxicity data for this substance.
LD/LC50 values that are relevant for classification:
No data
Skin irritation or corrosion:
Generally the product does not irritate the skin.
Eye irritation or corrosion:
No irritant effect.
No sensitizing effects known.
Germ cell mutagenicity:
No effects known.
No classification data on carcinogenic properties of this material is available from the EPA, IARC, NTP, OSHA or ACGIH.
Reproductive toxicity:
No effects known.
Specific target organ system toxicity - repeated exposure:
No effects known.
Specific target organ system toxicity - single exposure:
No effects known.
Aspiration hazard:
No effects known.
Subacute to chronic toxicity:
The Registry of Toxic Effects of Chemical Substances (RTECS) contains multiple dose toxicity
data for this substance.
Additional toxicological information:
To the best of our knowledge the acute and chronic toxicity of this substance is not fully known.
Carcinogenic categories
OSHA-Ca (Occupational Safety & Health Administration)
Substance is not listed.


Aquatic toxicity:
No further relevant information available.
Persistence and degradability
No further relevant information available.
Bioaccumulative potential
No further relevant information available.
Mobility in soil
No further relevant information available.
Additional ecological information:
General notes:
Do not allow material to be released to the environment without proper governmental permits.
Avoid transfer into the environment.
Results of PBT and vPvB assessment
Not applicable.
Not applicable.
Other adverse effects
No further relevant information available.


Waste treatment methods
Consult state, local or national regulations to ensure proper disposal.
Uncleaned packagings:
Disposal must be made according to official regulations.


Not applicable
UN proper shipping name
Not applicable
Transport hazard class(es)
Not applicable
Packing group
Not applicable
Environmental hazards:
Not applicable.
Special precautions for user
Not applicable.
Transport in bulk according to Annex II of MARPOL73/78 and the IBC Code
Not applicable.
Transport/Additional information:
Marine Pollutant (DOT):


Safety, health and environmental regulations/legislation specific for the substance or mixture
National regulations
All components of this product are listed in the U.S. Environmental Protection Agency Toxic Substances Control Act Chemical substance Inventory.
All components of this product are listed on the Canadian Non-Domestic Substances List (NDSL).
SARA Section 313 (specific toxic chemical listings)
Substance is not listed.
California Proposition 65
Prop 65 - Chemicals known to cause cancer
Substance is not listed.
Prop 65 - Developmental toxicity
Substance is not listed.
Prop 65 - Developmental toxicity, female
Substance is not listed.
Prop 65 - Developmental toxicity, male
Substance is not listed.
Information about limitation of use:
For use only by technically qualified individuals.
Other regulations, limitations and prohibitive regulations
Substance of Very High Concern (SVHC) according to the REACH Regulations (EC) No. 1907/2006.
Substance is not listed.
The conditions of restrictions according to Article 67 and Annex XVII of the Regulation (EC) No 1907/2006 (REACH) for the manufacturing, placing on the market and use must be observed.
Substance is not listed.
Annex XIV of the REACH Regulations (requiring Authorisation for use)
Substance is not listed.
REACH - Pre-registered substances
Substance is listed.
Chemical safety assessment:
A Chemical Safety Assessment has not been carried out.


Safety Data Sheet according to Regulation (EC) No. 1907/2006 (REACH). The above information is believed to be correct but does not purport to be all inclusive and shall be used only as a guide. The information in this document is based on the present state of our knowledge and is applicable to the product with regard to appropriate safety precautions. It does not represent any guarantee of the properties of the product. American Elements shall not be held liable for any damage resulting from handling or from contact with the above product. See reverse side of invoice or packing slip for additional terms and conditions of sale. COPYRIGHT 1997-2016 AMERICAN ELEMENTS. LICENSED GRANTED TO MAKE UNLIMITED PAPER COPIES FOR INTERNAL USE ONLY.

Germanium Isotopes

Germanium (Ge) has five naturally occurring isotopes, 70Ge, 72Ge, 73Ge, 74Ge, and 76Ge.

Nuclide Isotopic Mass Half-Life Mode of Decay Nuclear Spin Magnetic Moment Binding Energy (MeV) Natural Abundance
(% by atom)
58Ge 57.99101(34)# Unknown 2p to 56Zn 0+ N/A 441.04 -
59Ge 58.98175(30)# Unknown 2p to 57Zn 7/2-# N/A 458.44 -
60Ge 59.97019(25)# 30# ms ß+ to 60Ga; 2p to 58Zn 0+ N/A 476.77 -
61Ge 60.96379(32)# 39(12) ms ß+ + p to 60Zn; ß+ to 61Ga (3/2-)# N/A 491.37 -
62Ge 61.95465(15)# 129(35) ms ß+ to 62Ga 0+ N/A 507.83 -
63Ge 62.94964(21)# 142(8) ms ß+ to 63Ga (3/2-)# N/A 520.57 -
64Ge 63.94165(3) 63.7(25) s EC to 64Ga 0+ N/A 536.1 -
65Ge 64.93944(11) 30.9(5) s EC to 65Ga (3/2)- N/A 546.04 -
66Ge 65.93384(3) 2.26(5) h EC to 66Ga 0+ N/A 559.71 -
67Ge 66.932734(5) 18.9(3) min EC to 67Ga 1/2- N/A 568.72 -
68Ge 67.928094(7) 270.95(16) d EC to 68Ga 0+ N/A 580.52 -
69Ge 68.9279645(14) 39.05(10) h EC to 69Ga 5/2- 0.735 589.53 -
70Ge 69.9242474(11) STABLE - 0+ N/A 600.41 20.84
71Ge 70.9249510(11) 11.43(3) d EC to 71Ga 1/2- 0.547 608.49 -
72Ge 71.9220758(18) STABLE - 0+ N/A 618.43 27.54
73Ge 72.9234589(18) STABLE - 9/2+ -0.8794669 625.58 7.73
74Ge 73.9211778(18) STABLE - 0+ N/A 635.52 36.28
75Ge 74.9228589(18) 82.78(4) min ß- to 75As 1/2- 0.51 642.66 -
76Ge 75.9214026(18) 1.78(8)E+21 y - to 76Se 0+ N/A 651.67 7.61
77Ge 76.9235486(18) 11.30(1) h ß- to 77As 7/2+ N/A 657.89 -
78Ge 77.922853(4) 88(1) min ß- to 78As 0+ N/A 666.9 -
79Ge 78.9254(1) 18.98(3) s ß- to 79As (1/2)- N/A 672.18 -
80Ge 79.92537(3) 29.5(4) s ß- to 80As 0+ N/A 680.26 -
81Ge 80.92882(13) 7.6(6) s ß- to 81As 9/2+# N/A 685.55 -
82Ge 81.92955(26) 4.55(5) s ß- to 82As 0+ N/A 692.69 -
83Ge 82.93462(21)# 1.85(6) s ß- to 83As (5/2+)# N/A 696.11 -
84Ge 83.93747(32)# 0.947(11) s ß- to 84As; ß- + n to 83As 0+ N/A 701.4 -
85Ge 84.94303(43)# 535(47) ms ß- to 85As; ß- + n to 84As 5/2+# N/A 703.89 -
86Ge 85.94649(54)# >150 ns ß- + n to 85As; ß- to 86As 0+ N/A 709.17 -
87Ge 86.95251(54)# 0.14# s Unknown 5/2+# N/A 711.66 -
88Ge 87.95691(75)# >=300 ns Unknown 0+ N/A 716.01 -
89Ge 88.96383(97)# >150 ns Unknown 3/2+# N/A 717.57 -