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About Gadolinium

Gadolinium Bohr

Swiss chemist Jean Charles Galissard de Marignac discovered an oxide of an unknown element in a sample of gadolinite in 1880 and subsequently named the oxide “gadolinia”. The mineral had been named for Finnish chemist and geologist Johan Gadolin, who had discovered the first rare earth element, yttrium, in 1794. Thus gadolinium, named from its oxide, was only the second element to be named after an individual--the first being samarium, discovered just a year earlier, and which was also named after a mineral that had been named after a geologist.

Gadolinium has several properties that are key to its unique applications. It is probably best known for its magnetic properties. Gadolinium is ferromagnetic below 20 degrees Celsius and paramagnetic above this temperature. Due to these properties, gadolinium compounds are used to enhance contrast between normal and healthy tissue during magnetic resonance imaging (MRI) scanning. Gadolinium containing garnets have useful properties which lend them to applications in magneto-optical computer memory devices, however these types of computer memory have been replaced for most applications with alternative technologies that are faster and cheaper. Thin films of the magneto-optical material gadolinium-terbium-iron may also be use for these types of memory devices. Gadolinium also exhibits the magnetocaloric effect, meaning it experiences temperature changes when entering or exiting a magnetic field. This property is exploited gadolinium compounds used in magnetic refrigeration devices. Currently these devices are used primarily in research and industrial settings for ultra low temperature applications, however research developments may eventually make magnetic refrigeration a viable replacement for current commercial refrigeration technology.

An additional notable property of gadolinium is its high adsorption rate of neutrons. In nuclear energy applications, gadolinium is used in radiation shielding and in varying capacities to control the rate of the nuclear reaction. Gadolinium may also be used in neutron radiography, an imaging technology that uses neutrons much in the way x-rays are used in x-ray imaging. This technology is often used in industry for quality control when making precision parts. Gadolinium screens are used in neutron imaging to convert the neutrons that successfully pass through the imaged object into high-energy electrons which can then produce an image on x-ray film.

Gadolinium can also be used to produce compounds which exhibit luminescence either in response to the absorption of visible or near-visible light--these compounds are typically called phosphors--or in response to the absorption of ionizing radiation--these compounds are most often called scintillators. Gadolinium phosphors are used for green light in color display screens. Scintillator compounds containing gadolinium are used in sensors that detect X-rays or neutrons. These sensors are essential for the operation of medical imaging devices such as computed tomography scanners.

Gadolinium-153 is a radioactive isotope that is used in testing and calibration of medical imaging devices, bone density measurements, and in Lixiscope portable x-ray systems. Additionally, it has been investigated for potential use in radiotherapy for cancer.

In a few contexts, gadolinium is used in small quantities to alter the properties of a host material. In metallic alloys, gadolinium is used to to improve the workability of the material and increase resistance to high temperatures and oxidation. Gadolinium-doped garnets can be used in magneto-optical applications as previously mentioned, or may be used in microwave optical communications devices, lasers, or as imitation gemstones. Finally, gadolinium-doped ceria is an important potential electrolyte material for fuel cells, especially as it has higher ion conductivity and lower operating temperatures than the more commonly used yttria stabilized zirconia.

Several gadolinium compounds have been investigated for use as superconductors. Other uses currently in development for gadolinium include luminescent oxygen and temperature sensing compounds, novel high-k dielectrics for semiconductor devices, high temperature piezoelectric compounds for pressure and force detecting sensors, and compounds which can be used to immobilize and thus contain radioactive waste.

Gadolinium is a rare earth element that can be found in varying quantities in most rare-earth containing minerals. It is most commonly extracted from monazite and bastnasite.


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CUSTOMER ADVISORY: American Elements does not supply gadolinium for use in ANY form of GBCA (“Gadolinium-Based Contrast Agent”) or for ANY medical, pharmaceutical or nutritional use whatsoever or for the manufacture, testing, or development of ANY such products.

Gadolinium is utilized for both its high magnetic moment (7.94µB) and in phosphors and scintillator materials. When complexed with EDTA ligands, it is used as an High Purity (99.999%) Gadolinium (Gd) Sputtering Targetinjectable contrast agent for patients undergoing magnetic resonance imaging. With its high magnetic moment, gadolinium can reduce High Purity (99.999%) Gadolinium Oxide (Gd2O3) Powderrelaxation times and thereby enhance signal intensity. The extra stable half-full 4f electron shell with no low lying energy levels creates applications as an inert phosphor host. Gadolinium can therefore act as hosts for x-ray cassettes and in scintillator materials for computer tomography. Gadolinium is available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultra-high purity). Elemental or metallic forms include pellets, rod, wire and granules for evaporation source material purposes. Oxides are available in powder and dense pellet form 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. Gadolinium is also available in soluble forms including chlorides, nitrates and acetates. These compounds can be manufactured as solutions at specified stoichiometries.

Gadolinium Properties

Elemental GadoliniumGadolinium is a Block F, Group 3, Period 6 element. Gadolinium Bohr ModelThe number of electrons in each of Gadolinium's shells is 2, 8, 18, 25, 9, 2 and its electron configuration is [Xe] 4f7 5d1 6s2. The gadolinium atom has a radius of and its Van der Waals radius is In its elemental form, CAS 7440-54-2, gadolinium has a silvery-white appearance. Gadolinium was discovered by Jean Charles Galissard de Marignac in 1880 and first isolated by Lecoq de Boisbaudran in 1886. The element is named after the Finnish chemist and geologist Johan Gadolin.

Symbol: Gd
Atomic Number: 64
Atomic Weight: 157.25
Element Category: Lanthanide
Group, Period, Block: n/a, 6, f
Color: silvery-white
Other Names: Gadolinio, Gadolíneo
Melting Point: 1313°C, 2395.4°F, 1586.15 K
Boiling Point: 3273 °C, 5923.4 °F, 3546.15 K
Density: 7901 kg·m3
Liquid Density @ Melting Point: 7.4 g·cm3
Density @ 20°C: 7.895 g/cm3
Density of Solid: 7901 kg·m3
Specific Heat: 0.055 Cal/g/K @ 25°C
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): 15.5
Heat of Vaporization (kJ·mol-1): 301
Heat of Atomization (kJ·mol-1): 398.94
Thermal Conductivity: 0.105 W/cm/K @ 298.2 K
Thermal Expansion: (100 °C, poly) 9.4 µm/(m·K)
Electrical Resistivity: 140.5 µΩ-cm @ 25°C
Tensile Strength: N/A
Molar Heat Capacity: 37.03 J·mol-1·K-1
Young's Modulus: (? form) 54.8 GPa
Shear Modulus: (? form) 21.8 GPa
Bulk Modulus: (? form) 37.9 GPa
Poisson Ratio: (? form) 0.259
Mohs Hardness: N/A
Vickers Hardness: 570 MPa
Brinell Hardness: N/A
Speed of Sound: (20 °C) 2680 m·s-1
Pauling Electronegativity: 1.2
Sanderson Electronegativity: N/A
Allred Rochow Electronegativity: 1.11
Mulliken-Jaffe Electronegativity: N/A
Allen Electronegativity: N/A
Pauling Electropositivity: 2.8
Reflectivity (%): N/A
Refractive Index: N/A
Electrons: 64
Protons: 64
Neutrons: 93
Electron Configuration: [Xe] 4f7 5d1 6s2
Atomic Radius: 180 pm
Atomic Radius,
non-bonded (Å):
Covalent Radius: 196±6 pm
Covalent Radius (Å): 1.82
Van der Waals Radius: 237 pm
Oxidation States: 1, 2, 3 (mildly basic oxide)
Phase: Solid
Crystal Structure: hexagonal close-packed
Magnetic Ordering: ferromagnetic/paramagnetic
Electron Affinity (kJ·mol-1) Unknown
1st Ionization Energy: 593.40 kJ·mol-1
2nd Ionization Energy: 1166.52 kJ·mol-1
3rd Ionization Energy: 1990.51 kJ·mol-1
CAS Number: 7440-54-2
EC Number: 231-162-2
MDL Number: MFCD00011022
Beilstein Number: N/A
SMILES Identifier: [Gd]
InChI Identifier: InChI=1S/Gd
PubChem CID: 23982
ChemSpider ID: 22418
Earth - Total: 286 ppb
Mercury - Total: 220 ppb
Venus - Total: 300 ppb
Earth - Seawater (Oceans), ppb by weight: 0.0007
Earth - Seawater (Oceans), ppb by atoms: 0.000028
Earth -  Crust (Crustal Rocks), ppb by weight: 5200
Earth -  Crust (Crustal Rocks), ppb by atoms: 680
Sun - Total, ppb by weight: 2
Sun - Total, ppb by atoms: 0.01
Stream, ppb by weight: 0.04
Stream, ppb by atoms: 0.0003
Meterorite (Carbonaceous), ppb by weight: 230
Meterorite (Carbonaceous), ppb by atoms: 30
Typical Human Body, ppb by weight: N/A
Typical Human Body, ppb by atom: N/A
Universe, ppb by weight: 2
Universe, ppb by atom: 0.02
Discovered By: Jean Charles Galissard de Marignac
Discovery Date: 1880
First Isolation: Lecoq de Boisbaudran (1886)

Health, Safety & Transportation Information for Gadolinium

Gadolinium can be very toxic. Safety data for Gadolinium 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 material or compound referenced in the Products tab. The following applies to elemental (metallic) Gadolinium.

Safety Data
Signal Word Warning
Hazard Statements H261
Hazard Codes F
Risk Codes 15
Safety Precautions 43
RTECS Number N/A
Transport Information UN 3208 4.3 / PGIII
WGK Germany 3
Globally Harmonized System of
Classification and Labelling (GHS)
Review and Print SDS for Gadolinium Metal


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


Product Name: Gadolinium Metal

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

CAS #: 7440-54-2

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) = 1
Flammability = 1
Physical Hazard = 1
Other hazards
Results of PBT and vPvB assessment
PBT: Not applicable.
vPvB: Not applicable.


Chemical characterization: Substances
CAS# Description:
7440-54-2 Gadolinium
Identification number(s):
EC number: 231-162-2


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
Handle under dry protective gas.
Keep container tightly sealed.
Store in cool, dry place in tightly closed containers.
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:
Do not store together with oxidizing and acidic materials.
Store away from air.
Store away from water/moisture.
Further information about storage conditions:
Store under dry inert gas.
This product is moisture sensitive.
This product is air sensitive.
Keep container tightly sealed.
Store in cool, dry conditions in well sealed containers.
Protect from humidity and water.
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-colored
Odor: Not determined
Odor threshold: Not determined.
pH-value: Not applicable.
Change in condition
Melting point/Melting range: 1312 °C (2394 °F)
Boiling point/Boiling range: 3273 °C (5923 °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): 7.9 g/cm³ (65.926 lbs/gal)
Relative density: Not determined.
Vapor density: Not applicable.
Evaporation rate: Not applicable.
Solubility in / Miscibility with Water: Not determined
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
Spontaneously flammable in air.
Conditions to avoid
No further relevant information available.
Incompatible materials:
Oxidizing agents
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: May cause irritation
Eye irritation or corrosion: May cause irritation
Sensitization: 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: 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.
Do not allow undiluted product or large quantities to reach ground water, water course or sewage system.
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.


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):
UN ""Model Regulation"":


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) accord
ing 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.

Gadolinium Isotopes

Gadolinium (Gd) has 6 stable isotopes: 154Gd, 155Gd, 156Gd, 157Gd, 158Gd and 160Gd.

Nuclide Isotopic Mass Half-Life Mode of Decay Nuclear Spin Magnetic Moment Binding Energy (MeV) Natural Abundance
(% by atom)
134Gd 133.95537(43)# 0.4# s Unknown 0+ N/A 1057.32 -
135Gd 134.95257(54)# 1.1(2) s Unknown 3/2- N/A 1065.4 -
136Gd 135.94734(43)# 1# s [>200 ns] ß+ to 136Eu N/A N/A 1082.79 -
137Gd 136.94502(43)# 2.2(2) s ß+ to 137Eu 7/2+# N/A 1090.87 -
138Gd 137.94012(21)# 4.7(9) s ß+ to 138Eu 0+ N/A 1098.95 -
139Gd 138.93824(21)# 5.7(3) s ß+ to 139Eu 9/2-# N/A 1116.34 -
140Gd 139.93367(3) 15.8(4) s ß+ to 140Eu 0+ N/A 1124.42 -
141Gd 140.932126(21) 14(4) s ß+ to 141Eu; ß+ + p to 140Sm (1/2+) N/A 1132.5 -
142Gd 141.92812(3) 70.2(6) s ß+ to 142Eu 0+ N/A 1149.89 -
143Gd 142.92675(22) 39(2) s ß+ to 143Eu (1/2)+ N/A 1157.97 -
144Gd 143.92296(3) 4.47(6) min ß+ to 144Eu 0+ N/A 1166.05 -
145Gd 144.921709(20) 23.0(4) min ß+ to 145Eu 1/2+ N/A 1174.13 -
146Gd 145.918311(5) 48.27(10) d EC to 146Eu 0+ N/A 1191.53 -
147Gd 146.919094(3) 38.06(12) h EC to 147Eu 7/2- 1 1199.6 -
148Gd 147.918115(3) 74.6(30) y a to 144Sm 0+ N/A 1207.68 -
149Gd 148.919341(4) 9.28(10) d EC to 149Eu; a to 145Sm 7/2- 0.9 1215.76 -
150Gd 149.918659(7) 1.79(8)E+6 y a to 146Sm 0+ N/A 1223.84 -
151Gd 150.920348(4) 124(1) d EC to 151Eu; a to 147Sm 7/2- 0.8 1222.6 -
152Gd 151.9197910(27) 1.08(8)E+14 y a to 148Sm 0+ N/A 1240 0.2
153Gd 152.9217495(27) 240.4(10) d EC to 153Eu 3/2- 0.4 1238.76 -
154Gd 153.9208656(27) Observationally Stable - 0+ N/A 1246.84 2.18
155Gd 154.9226220(27) Observationally Stable - 3/2- -0.2591 1254.92 14.8
156Gd 155.9221227(27) STABLE - 0+ N/A 1263 20.47
157Gd 156.9239601(27) STABLE - 3/2- -0.3399 1271.08 15.65
158Gd 157.9241039(27) STABLE - 0+ N/A 1279.15 24.84
159Gd 158.9263887(27) 18.479(4) h ß- to 159Tb 3/2- -0.44 1287.23 -
160Gd 159.9270541(27) Observationally Stable - 0+ N/A 1295.31 21.86
161Gd 160.9296692(29) 3.646(3) min ß- to 161Tb 5/2- N/A 1303.39 -
162Gd 161.930985(5) 8.4(2) min ß- to 162Tb 0+ 2 1302.15 -
163Gd 162.93399(32)# 68(3) s ß- to 163Tb 7/2+# N/A 1310.23 -
164Gd 163.93586(43)# 45(3) s ß- to 164Tb 0+ 1.9 1318.31 -
165Gd 164.93938(54)# 10.3(16) s ß- to 165Tb 1/2-# N/A 1326.39 -
166Gd 165.94160(64)# 4.8(10) s ß- to 166Tb 0+ 1.8 1325.15 -
167Gd 166.94557(64)# 3# s ß- to 167Tb 5/2-# N/A 1333.23 -
168Gd 167.94836(75)# 300# ms ß- to 168Tb 0+ 1.4 1341.31 -
169Gd 168.95287(86)# 1# s ß- to 169Tb 7/2-# N/A 1340.07 -