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About Gallium

Gallium Bohr

Just four years after Dmitri Mendeleev published his 1871 periodic table that predicted element 31 and gave it the tentative name eka-aluminum, spectroscopic evidence for the existence of the element was detected in a sphalerite sample by Paul-Émile Lecoq de Boisbaudran. Lecoq later went on to discover more elements, but he named gallium, his first, from the Latin for Gaul, the area occupied by his native France. For the following eighty-five years, it was primarily a curiosity--a metal that is solid around room temperature, but liquefies when held in the hand--but did find some use in the preparation of metal alloys with special properties such as low-melting points, in high-temperature thermometers, and as the reflective compound in mirrors.

Gallium use changed forever in the 1960’s, when gallium arsenide was developed as a semiconductor with somewhat different electrical properties than the more common silicon, and that is more suited than silicon to some applications. Notably, gallium arsenide is a direct band gap semiconductor, which means that it can both absorb and emit light with high efficiency. This lends it to use in LEDs and lasers. Additionally, extremely thin layers of gallium arsenide can effectively absorb all the photons from incident sunlight, as opposed to the thick layers of silicon required for the same task. This allows for the creation of one type of thin-film solar cell. Gallium arsenide semiconductor devices also exhibit less noise than those produced from silicon, and are thus favored in many telecommunications applications.

In addition to being a component of gallium arsenide, gallium can be used to make several other semiconducting compounds. The gallium semiconductors are used in many applications, including light-emitting devices such as LEDs and lasers, photovoltaic and thermophotovoltaic cells, and integrated circuits. Gallium also finds use in a few highly specialized technical applications, including in neutrino-detecting telescopes, notable for the sheer volume of gallium they can require--the Gallium-Germanium Neutrino Telescope used by the SAGE experiment at the Baksan Neutrino Observatory in Russia used at least 55 tons of the liquid metal. It can also serve as a liquid metal ion source for focused ion devices. Gadolinium gallium garnets are used to fabricate optical components and as a substrate material for magneto-optical films and high-temperature superconductors. Finally, gallium phosphate is a piezoelectric material that can function at high temperatures unlike alternatives such as quartz, which makes it useful for pressure and force sensors in high-temperature applications.

Gallium is not a compound naturally involved in human biology, but because it is generally considered non-toxic at low doses and mimics some of the properties of iron in the body, it is useful in some medical applications. Gallium tends to concentrate in areas of high levels of inflammation and cell growth, and therefore radioactive isotopes of the element are used in scans for tracking the spread of some cancers and disorders of the immune system. Additionally, gallium salts are used to treat hypercalcemia that results from cancers metastasizing to the bones, and are under investigation as treatment for certain types of cancers. Gallium compounds are also known to be toxic to some disease-causing microorganisms, and organometallic gallium compounds have shown some promise as potential malaria treatments.

The few minerals which contain substantial percentages of gallium are too rare to serve as a commercially viable source of the element. Gallium is found in small amounts in the aluminum ore bauxite and the zinc ore sphalerite, and is therefore extracted from waste materials from the processing of these metals.


Semiconductor & Optical
Sputtering Targets
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High Purity (99.999%) Gallium (Ga) Sputtering Target Gallium has received much attention in relation to its application in the production of semiconducting compounds. Of these, the most important are the compounds of gallium with antimony, arsenic or phosphor. Gallium arsenide (GaAs) is used in the production of diodes and transistors for voltage rectification and signal amplification. Other gallium arsenide applications include semiconductor "lasing" and microwave generation. Gallium is also used in sensors to measure temperature, light or magnetic field. High Purity (99.999%) Gallium Oxide (Ga2O3) Powder Elemental or metallic forms of gallium include pellets for evaporation source material purposes. Gallium oxide is available in forms including powders and dense pellets for use as optical coating and thin film applications. Oxides tend to be insoluble. Gallium fluoride is another insoluble form for uses in which oxygen is undesirable such as metallurgy, chemical and physical vapor deposition and in some optical coatings. Gallium is available in soluble forms including chlorides, nitrates and acetates. These compounds can be manufactured as solutions at specified stoichiometries.

Gallium Properties

Gallium (Ga) atomic and molecular weight, atomic number and elemental symbolGallium is a Block P, Group 13, Period 4 element. The number of electrons in each of Gallium's shells is 2, 8, 18, 3 and its electron configuration is [Ar] 3d10 4s2 4p1. The gallium atom has a radius of and its Van der Waals radius is In its elemental form, CAS 7440-55-3, gallium has a silvery appearance. Gallium Bohr Modelhigh purity properties, and other useful facts are discussed below. Scientific facts such as the atomic structure, ionization energy, abundance on earth, conductivity and thermal properties are also included.

Symbol: Ga
Atomic Number: 31
Atomic Weight: 69.723
Element Category: post-transition metal
Group, Period, Block: 13, 4, p
Color: silvery white/ silvery-blue
Other Names: N/A
Melting Point: 29.765°C, 85.576°F, 302.915 K
Boiling Point: 2229°C, 4044.2°F, 2502.15 K
Density: 5.91 g·cm3
Liquid Density @ Melting Point: 6.095 g·cm3
Density @ 20°C: 5.907 g/cm3
Density of Solid: 5904 kg·m3
Specific Heat: 0.372 @20°C J/g mol
Superconductivity Temperature: 1.083 [or -272.067 °C (-457.72 °F)] K
Triple Point: N/A
Critical Point: N/A
Heat of Fusion (kJ·mol-1): 5.59
Heat of Vaporization (kJ·mol-1): 270.3
Heat of Atomization (kJ·mol-1): 276
Thermal Conductivity: 40.6 W·m-1·K-1
Thermal Expansion: (25 °C) 18 µm·mol-1·K-1
Electrical Resistivity: (20 °C) 270 nΩ·m
Tensile Strength: N/A
Molar Heat Capacity: 25.86 J·mol-1·K-1
Young's Modulus: 9.8 GPa
Shear Modulus: N/A
Bulk Modulus: N/A
Poisson Ratio: 0.47
Mohs Hardness: 1.5
Vickers Hardness: N/A
Brinell Hardness: 60 MPa
Speed of Sound: (20 °C) 2740 m·s-1
Pauling Electronegativity: 1.81
Sanderson Electronegativity: 2.42
Allred Rochow Electronegativity: 1.82
Mulliken-Jaffe Electronegativity: 2.01 (sp2 orbital)
Allen Electronegativity: 1.756
Pauling Electropositivity: 2.19
Reflectivity (%): N/A
Refractive Index: N/A
Electrons: 31
Protons: 31
Neutrons: 39
Electron Configuration: [Ar] 3d10 4s2 4p1
Atomic Radius: 135 pm
Atomic Radius,
non-bonded (Å):
Covalent Radius: 122±3 pm
Covalent Radius (Å): 1.23
Van der Waals Radius: 187 pm
Oxidation States: 3, 2, 1 (amphoteric oxide)
Phase: Solid
Crystal Structure: orthorhombic
Magnetic Ordering: diamagnetic
Electron Affinity (kJ·mol-1) 41.474
1st Ionization Energy: 578.85 kJ·mol-1
2nd Ionization Energy: 1979.33 kJ·mol-1
3rd Ionization Energy: 2963.09 kJ·mol-1
CAS Number: 7440-55-3
EC Number: 231-163-8
MDL Number: MFCD00134045
Beilstein Number: N/A
SMILES Identifier: [Ga]
InChI Identifier: InChI=1S/Ga
PubChem CID: 23981
ChemSpider ID: 4514603
Earth - Total: 3.1 ppm 
Mercury - Total: 0.50 ppm
Venus - Total: 3.4 ppm 
Earth - Seawater (Oceans), ppb by weight: 0.03
Earth - Seawater (Oceans), ppb by atoms: 0.0027
Earth -  Crust (Crustal Rocks), ppb by weight: 19000
Earth -  Crust (Crustal Rocks), ppb by atoms: 5500
Sun - Total, ppb by weight: 40
Sun - Total, ppb by atoms: 0.6
Stream, ppb by weight: 0.15
Stream, ppb by atoms: 0.002
Meterorite (Carbonaceous), ppb by weight: 7800
Meterorite (Carbonaceous), ppb by atoms: 2000
Typical Human Body, ppb by weight: N/A
Typical Human Body, ppb by atom: N/A
Universe, ppb by weight: 10
Universe, ppb by atom: 0.2
Discovered By: Lecoq de Boisbaudran
Discovery Date: 1875
First Isolation: Lecoq de Boisbaudran (1875)

Health, Safety & Transportation Information for Gallium

Gallium is not toxic in its elemental form; however, safety data for Gallium 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 Gallium material or compound referenced in the “Gallium Products” tab.

Safety Data
Signal Word Danger
Hazard Statements H314
Hazard Codes C
Risk Codes 34
Safety Precautions 26-36/37/39-45
RTECS Number LW8600000
Transport Information UN 2803 8/PG 3
WGK Germany 3
Globally Harmonized System of
Classification and Labelling (GHS)
Corrosion-Corrosive to metals
Review and Print SDS for Gallium Metal


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


Product Name: Gallium Metal

Product Number: All applicable American Elements product codes, e.g. GA-M-02, GA-M-03, GA-M-04, GA-M-05, GA-M-06, GA-M-07

CAS #: 7440-55-3

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
GHS05 Corrosion
Met. Corr.1 H290 May be corrosive to metals.
Classification according to Directive 67/548/EEC or Directive 1999/45/EC
Not applicable
Information concerning particular hazards for human and environment:
Not applicable
Hazards not otherwise classified
No information known.
Label elements
Labelling according to Regulation (EC) No 1272/2008
The substance is classified and labeled according to the CLP regulation.
Hazard pictograms

Corrosion - GHS05

Signal word
Hazard statements
H290 May be corrosive to metals.
Precautionary statements
P234 Keep only in original container.
P390 Absorb spillage to prevent material damage.
P406 Store in corrosive resistant container with a resistant inner liner.
WHMIS classification
E - Corrosive material
Classification system
HMIS ratings (scale 0-4)
(Hazardous Materials Identification System)

Health (acute effects) = 1
Flammability = 0
Physical Hazard = 1
Other hazards
Results of PBT and vPvB assessment
Not applicable.
Not applicable


Chemical characterization: Substances
CAS# Description:
7440-55-3 Gallium
Identification number(s):
EC number:


Description of first aid measures
After inhalation
Supply fresh air. If required, provide artificial respiration. Keep patient warm.
Seek immediate medical advice.
After skin contact
Immediately wash with water and soap and rinse thoroughly.
Seek immediate medical advice.
After eye contact
Rinse opened eye for several minutes under running water. Then consult a doctor.
After swallowing
Seek medical treatment.
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:
Wear self-contained respirator.
Wear fully protective impervious suit.


Personal precautions, protective equipment and emergency procedures
Wear protective equipment. Keep unprotected persons away.
Ensure adequate ventilation
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.
Ensure good ventilation at the workplace.
Information about protection against explosions and fires:
No information known.
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:
Store away from halogens.
Do not store together with oxidizing and acidic materials.
Store away from aluminum, aluminum alloys
Store away from magnesium/magnesium alloys
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:
Properly operating chemical fume hood designed for hazardous chemicals and
having an average face velocity of at least 100 feet per minute.
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.
Keep away from foodstuffs, beverages and feed.
Remove all soiled and contaminated clothing immediately.
Wash hands before breaks and at the end of work.
Maintain an ergonomically appropriate working environment.
Breathing equipment:
Use suitable respirator when high concentrations are present.
Protection of hands:
Impervious gloves
Check protective gloves prior to each use for their proper condition.
The selection of suitable gloves not only depends on the material, but also on quality. Quality will vary from manufacturer to manufacturer.
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 grey
Odor: Not determined
Odor threshold: Not determined.
pH-value: Not applicable.
Change in condition
Melting point/Melting range: 29.8 °C (86 °F)
Boiling point/Boiling range: 2403 °C (4357 °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: Not applicable.
Density at 20 °C (68 °F): 5.91 g/cm³ (49.319 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:
Oxidizing agents
Aluminum/aluminum alloys.
Magnesium/magnesium alloys
Hazardous decomposition products:
Metal oxide fume


Information on toxicological effects
Acute toxicity:
No effects known.
LD/LC50 values that are relevant for classification:
No data
Skin irritation or corrosion:
Product is not corrosive to the skin.
Eye irritation or corrosion:
Product is not corrosive to the eyes.
No sensitizing effects known.
Germ cell mutagenicity:
The Registry of Toxic Effects of Chemical Substances (RTECS) contains mutation data for this substance.
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:
No effects known.
Additional toxicological information:
To the best of our knowledge the acute and chronic toxicity of this substance is not fully known.


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.


UN proper shipping name
Transport hazard class(es)
8 Corrosive substances.
8 (C10) Corrosive substances
8 Corrosive substances.
Packing group
Environmental hazards:
Not applicable.
Special precautions for user
Warning: Corrosive substances
Transport in bulk according to Annex II of MARPOL73/78 and the IBC Code
Not applicable.
Transport/Additional information:
Marine Pollutant (DOT):
UN "Model Regulation":
UN2803, Gallium, 8, IIl


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 Domestic Substances List (DSL).
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.

Gallium Isotopes

Gallium (Ga) has two stable isotopes: gallium-69 and gallium-71.

Nuclide Isotopic Mass Half-Life Mode of Decay Nuclear Spin Magnetic Moment Binding Energy (MeV) Natural Abundance
(% by atom)
56Ga 55.99491(28)# N/A p to 55Zn 3+# N/A 423.21 -
57Ga 56.98293(28)# N/A p to 56Zn 1/2-# N/A 442.47 -
58Ga 57.97425(23)# N/A p to 57Zn 2+# N/A 458 -
59Ga 58.96337(18)# N/A p to 58Zn 3/2-# N/A 476.33 -
60Ga 59.95706(12)# 70(10) ms ß+ to 60Zn (2+) N/A 490 -
61Ga 60.94945(6) 168(3) ms ß+ to 61Zn 3/2- N/A 505.53 -
62Ga 61.944175(30) 116.18(4) ms ß+ to 62Zn 0+ N/A 518.27 -
63Ga 62.9392942(14) 32.4(5) s ß+ to 63Zn (3/2-) N/A 531 -
64Ga 63.9368387(22) 2.627(12) min EC to 64Zn 0(+#) N/A 541.88 -
65Ga 64.9327348(9) 15.2(2) min EC to 65Zn 3/2- N/A 553.68 -
66Ga 65.931589(3) 9.49(7) h EC to 66Zn 0+ N/A 562.69 -
67Ga 66.9282017(14) 3.2612(6) d EC to 67Zn 3/2- 1.8507 573.57 -
68Ga 67.9279801(16) 67.71(9) min EC to 68Zn 1+ 0.01175 582.58 -
69Ga 68.9255736(13) STABLE - 3/2- 2.01659 592.52 60.108
70Ga 69.9260220(13) 21.14(3) min EC to 70Zn; ß- to 70Ge 1+ N/A 599.67 -
71Ga 70.9247013(11) STABLE - 3/2- 2.56227 609.61 39.892
72Ga 71.9263663(11) 14.095(3) h ß- to 72Ge 3- -0.13224 615.82 -
73Ga 72.9251747(18) 4.86(3) h ß- to 73Ge 3/2- N/A 624.83 -
74Ga 73.926946(4) 8.12(12) min ß- to 74Ge (3-) N/A 631.98 -
75Ga 74.9265002(26) 126(2) s ß- to 75Ge (3/2)- N/A 640.06 -
76Ga 75.9288276(21) 32.6(6) s ß- to 76Ge (2+,3+) N/A 646.28 -
77Ga 76.9291543(26) 13.2(2) s ß- to 77Ge (3/2-) N/A 653.42 -
78Ga 77.9316082(26) 5.09(5) s ß- to 78Ge (3+) N/A 659.64 -
79Ga 78.93289(11) 2.847(3) s ß- to 79Ge; ß- + n to 78Ge (3/2-)# N/A 666.78 -
80Ga 79.93652(13) 1.697(11) s ß- to 80Ge; ß- + n to 79Ge -3 N/A 671.14 -
81Ga 80.93775(21) 1.217(5) s ß- to 81Ge; ß- + n to 80Ge (5/2-) N/A 678.28 -
82Ga 81.94299(32)# 0.599(2) s ß- to 82Ge; ß- + n to 81Ge (1,2,3) N/A 681.7 -
83Ga 82.94698(32)# 308(1) ms ß- to 83Ge; ß- + n to 82Ge 3/2-# N/A 686.06 -
84Ga 83.95265(43)# 0.085(10) s ß- + n to 73Ge; ß- to 84Ge N/A N/A 688.55 -
85Ga 84.95700(54)# 50# ms [>300 ns] Unknown 3/2-# N/A 691.97 -
86Ga 85.96312(86)# 30# ms [>300 ns] Unknown N/A N/A 694.46 -