Germanium

72.64

About Germanium

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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Isotopes

Germanium is a very important semiconductor and 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 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 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 Model The germanium atom has a radius of 122.5.pm and its Van der Waals radius is 211.pm. 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 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".

General Properties

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

Physical Properties

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

Chemical Properties

Electrons:	32
Protons:	32
Neutrons:	41
Electron Configuration:	[Ar] 3d¹⁰ 4s² 4p²
Atomic Radius:	122 pm
Atomic Radius, non-bonded (Å):	2.11
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
1^st Ionization Energy:	762.18 kJ·mol^-1
2^nd Ionization Energy:	1537.47 kJ·mol^-1
3^rd Ionization Energy:	3302.15 kJ·mol^-1

Identifiers

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
InChI Key:	GNPVGFCGXDBREM-UHFFFAOYSA-N
PubChem CID:	6326954
ChemSpider ID:	4885606

abundance

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

History

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)

Review and Print SDS for Germanium Metal

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SAFETY DATA SHEET

Date Created: 05/15/2015

Date Revised: 05/15/2015

SECTION 1. IDENTIFICATION

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

SECTION 2. HAZARDS IDENTIFICATION

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

SECTION 3. COMPOSITION/INFORMATION ON INGREDIENTS

Chemical characterization: Substances
CAS# Description:
7440-56-4 Germanium
Identification number(s):
EC number:
231-164-3

SECTION 4. FIRST AID MEASURES

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.

SECTION 5. FIREFIGHTING MEASURES

Extinguishing media
Suitable extinguishing agents
Special powder for metal fires. Do not use water.
For safety reasons unsuitable extinguishing agents
Water
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

SECTION 6. ACCIDENTAL RELEASE MEASURES

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.

SECTION 7. HANDLING AND STORAGE

Handling
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
Storage
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.

SECTION 8. EXPOSURE CONTROLS/PERSONAL PROTECTION

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.

SECTION 9. PHYSICAL AND CHEMICAL PROPERTIES

Information on basic physical and chemical properties
General Information
Appearance:
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.
Viscosity:
dynamic: Not applicable.
kinematic: Not applicable.
Other information
No further relevant information available.

SECTION 10. STABILITY AND REACTIVITY

Reactivity
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

SECTION 11. TOXICOLOGICAL INFORMATION

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.
Sensitization:
No sensitizing effects known.
Germ cell mutagenicity:
No effects known.
Carcinogenicity:
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.

SECTION 12. ECOLOGICAL INFORMATION

Toxicity
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
PBT:
Not applicable.
vPvB:
Not applicable.
Other adverse effects
No further relevant information available.

SECTION 13. DISPOSAL CONSIDERATIONS

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

SECTION 14. TRANSPORT INFORMATION

UN-Number
DOT, ADN, IMDG, IATA
Not applicable
UN proper shipping name
DOT, ADN, IMDG, IATA
Not applicable
Transport hazard class(es)
DOT, ADR, ADN, IMDG, IATA
Class
Not applicable
Packing group
DOT, IMDG, IATA
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:
DOT
Marine Pollutant (DOT):
No

SECTION 15. REGULATORY INFORMATION

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.

16. OTHER INFORMATION

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	2ß^- 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	-