Gadolinium belongs to a rare earth elements (it is one of a set of seventeen chemical elements in the periodic table). In nuclear industry gadolinium is commonly used as a neutron absorber due to very high neutron absorbtion cross-section of two isotopes 155Gd and 157Gd. In fact their absorption cross-sections are the highest among all stable isotopes.
|Element category||Rare Earth Metal|
|Phase at STP||Solid|
|Ultimate Tensile Strength||170 MPa|
|Yield Strength||160 MPa|
|Young’s Modulus of Elasticity||54.8 GPa|
|Vickers Hardness||570 MPa|
|Melting Point||1313 °C|
|Boiling Point||3000 °C|
|Thermal Conductivity||11 W/mK|
|Thermal Expansion Coefficient||9.4 µm/mK|
|Specific Heat||0.23 J/g K|
|Heat of Fusion||10.05 kJ/mol|
|Heat of Vaporization||359.4 kJ/mol|
|Electrical resistivity [nanoOhm meter]||1310|
|Magnetic Susceptibility||+755000e-6 cm^3/mol|
Applications of Gadolinium
Gadolinium possesses unusual metallurgical properties, to the extent that as little as 1% of gadolinium can significantly improve the workability and resistance to oxidation at high temperatures of iron, chromium, and related metals. Gadolinium as a metal or a salt absorbs neutrons and is, therefore, used sometimes for shielding in neutron radiography and in nuclear reactors. Gadolinium is widely used as a burnable absorber, which is commonly used in fresh fuel to compensate an excess of reactivity of reactor core. Among all known stable elements, gadolinium has the highest thermal neutron capture cross-section (49,000 barns). Gadolinium barium copper oxide (GdBCO) has been researched for its superconducting properties with applications in superconducting motors or generators – for example in a wind turbine.
Production and Price of Gadolinium
Raw materials prices change daily. They are primarily driven by supply, demand and energy prices. In 2019, prices of pure Gadolinium were at around 1910 $/kg.
Gadolinium is produced both from monazite and bastnäsite. Commercially, it is recovered from monazite sand and bastnasite by extraction processes and ion exchange techniques. Monazite is an important ore for thorium, lanthanum, and cerium. It is often found in placer deposits. India, Madagascar, and South Africa have large deposits of monazite sands. The deposits in India are particularly rich in monazite.
Mechanical Properties of Gadolinium
Strength of Gadolinium
In mechanics of materials, the strength of a material is its ability to withstand an applied load without failure or plastic deformation. Strength of materials basically considers the relationship between the external loads applied to a material and the resulting deformation or change in material dimensions. In designing structures and machines, it is important to consider these factors, in order that the material selected will have adequate strength to resist applied loads or forces and retain its original shape. Strength of a material is its ability to withstand this applied load without failure or plastic deformation.
For tensile stress, the capacity of a material or structure to withstand loads tending to elongate is known as ultimate tensile strength (UTS). Yield strength or yield stress is the material property defined as the stress at which a material begins to deform plastically whereas yield point is the point where nonlinear (elastic + plastic) deformation begins.
See also: Strength of Materials
Ultimate Tensile Strength of Gadolinium
Ultimate tensile strength of Gadolinium is 170 MPa.
Yield Strength of Gadolinium
Yield strength of Gadolinium is 160 MPa.
Modulus of Elasticity of Gadolinium
The Young’s modulus of elasticity of Gadolinium is 160 MPa.
Hardness of Gadolinium
In materials science, hardness is the ability to withstand surface indentation (localized plastic deformation) and scratching. Brinell hardness test is one of indentation hardness tests, that has been developed for hardness testing. In Brinell tests, a hard, spherical indenter is forced under a specific load into the surface of the metal to be tested.
Brinell hardness of Gadolinium is approximately N/A.
The Vickers hardness test method was developed by Robert L. Smith and George E. Sandland at Vickers Ltd as an alternative to the Brinell method to measure the hardness of materials. The Vickers hardness test method can be also used as a microhardness test method, which is mostly used for small parts, thin sections, or case depth work.
Vickers hardness of Gadolinium is approximately 570 MPa.
Scratch hardness is the measure of how resistant a sample is to permanent plastic deformation due to friction from a sharp object. The most common scale for this qualitative test is Mohs scale, which is used in mineralogy. The Mohs scale of mineral hardness is based on the ability of one natural sample of mineral to scratch another mineral visibly.
Gadolinium is has a hardness of approximately N/A.
See also: Hardness of Materials
Gadolinium – Crystal Structure
A possible crystal structure of Gadolinium is hexagonal close-packed structure.
In metals, and in many other solids, the atoms are arranged in regular arrays called crystals. A crystal lattice is a repeating pattern of mathematical points that extends throughout space. The forces of chemical bonding causes this repetition. It is this repeated pattern which control properties like strength, ductility, density, conductivity (property of conducting or transmitting heat, electricity, etc.), and shape. There are 14 general types of such patterns known as Bravais lattices.
See also: Crystal Structure of Materials
Crystal Structure of Gadolinium
Thermal Properties of Gadolinium
Gadolinium – Melting Point and Boiling Point
Melting point of Gadolinium is 1313°C.
Boiling point of Gadolinium is 3000°C.
Note that, these points are associated with the standard atmospheric pressure.
Gadolinium – Thermal Conductivity
Thermal conductivity of Gadolinium is 11 W/(m·K).
The heat transfer characteristics of a solid material are measured by a property called the thermal conductivity, k (or λ), measured in W/m.K. It is a measure of a substance’s ability to transfer heat through a material by conduction. Note that Fourier’s law applies for all matter, regardless of its state (solid, liquid, or gas), therefore, it is also defined for liquids and gases.
Coefficient of Thermal Expansion of Gadolinium
Linear thermal expansion coefficient of Gadolinium is 9.4 µm/(m·K)
Thermal expansion is generally the tendency of matter to change its dimensions in response to a change in temperature. It is usually expressed as a fractional change in length or volume per unit temperature change.
Gadolinium – Specific Heat, Latent Heat of Fusion, Latent Heat of Vaporization
Specific heat of Gadolinium is 0.23 J/g K.
Heat capacity is an extensive property of matter, meaning it is proportional to the size of the system. Heat capacity C has the unit of energy per degree or energy per kelvin. When expressing the same phenomenon as an intensive property, the heat capacity is divided by the amount of substance, mass, or volume, thus the quantity is independent of the size or extent of the sample.
Latent Heat of Fusion of Gadolinium is 10.05 kJ/mol.
Latent Heat of Vaporization of Gadolinium is 359.4 kJ/mol.
Latent heat is the amount of heat added to or removed from a substance to produce a change in phase. This energy breaks down the intermolecular attractive forces, and also must provide the energy necessary to expand the gas (the pΔV work). When latent heat is added, no temperature change occurs. The enthalpy of vaporization is a function of the pressure at which that transformation takes place.
Gadolinium – Electrical Resistivity – Magnetic Susceptibility
Electrical property refers to the response of a material to an applied electric field. One of the principal characteristics of materials is their ability (or lack of ability) to conduct electrical current. Indeed, materials are classified by this property, that is, they are divided into conductors, semiconductors, and nonconductors.
See also: Electrical Properties
Magnetic property refers to the response of a material to an applied magnetic field. The macroscopic magnetic properties of a material are a consequence of interactions between an external magnetic field and the magnetic dipole moments of the constituent atoms. Different materials react to the application of magnetic field differently.
See also: Magnetic Properties
Electrical Resistivity of Gadolinium
Electrical resistivity of Gadolinium is 1310 nΩ⋅m.
Electrical conductivity and its converse, electrical resistivity, is a fundamental property of a material that quantifies how Gadolinium conducts the flow of electric current. Electrical conductivity or specific conductance is the reciprocal of electrical resistivity.
Magnetic Susceptibility of Gadolinium
Magnetic susceptibility of Gadolinium is +755000e-6 cm^3/mol.
In electromagnetism, magnetic susceptibility is the measure of the magnetization of a substance. Magnetic susceptibility is a dimensionless proportionality factor that indicates the degree of magnetization of Gadolinium in response to an applied magnetic field.
Application and prices of other elements