Cerium is a soft, ductile and silvery-white metal that tarnishes when exposed to air, and it is soft enough to be cut with a knife. Cerium is the second element in the lanthanide series. Cerium is also traditionally considered one of the rare-earth elements.
|Element category||Rare Earth Metal|
|Phase at STP||Solid|
|Ultimate Tensile Strength||100 MPa|
|Yield Strength||90 MPa|
|Young’s Modulus of Elasticity||33.6 GPa|
|Brinell Hardness||412 MPa|
|Vickers Hardness||300 MPa|
|Melting Point||798 °C|
|Boiling Point||3457 °C|
|Thermal Conductivity||11 W/mK|
|Thermal Expansion Coefficient||6.3 µm/mK|
|Specific Heat||0.19 J/g K|
|Heat of Fusion||5.46 kJ/mol|
|Heat of Vaporization||414 kJ/mol|
|Electrical resistivity [nanoOhm meter]||828|
|Magnetic Susceptibility||+2450e-6 cm^3/mol|
Applications of Cerium
Cerium is an important component of mischmetal alloy. Ferrocerium is a synthetic pyrophoric alloy that produces hot sparks that can reach temperatures of 3,000 °C (5,430 °F) when rapidly oxidized by the process of striking the rod, thereby fragmenting it and exposing those fragments to the oxygen in the air. A typical composition includes approximately 55% cerium, 25% lanthanum, and 15-18% neodymium with other rare earth metals following. The best-known use for this alloy is in ‘flints’ for cigarette lighters. Ceria is the most widely used compound of cerium. The main application of ceria is as a polishing compound, for example in chemical-mechanical planarization (CMP).
Production and Price of Cerium
Raw materials prices change daily. They are primarily driven by supply, demand and energy prices. In 2019, prices of pure Cerium were at around 570 $/kg.
The ores containing cerium, such as monazite, are typically contain a range of other rare earths. Consequently they undergo a series of chemical treatments to remove rare earths such as thorium and cerium. 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 Cerium
Strength of Cerium
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 Cerium
Ultimate tensile strength of Cerium is 100 MPa.
Yield Strength of Cerium
Yield strength of Cerium is 90 MPa.
Modulus of Elasticity of Cerium
The Young’s modulus of elasticity of Cerium is 90 MPa.
Hardness of Cerium
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 Cerium is approximately 412 MPa.
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 Cerium is approximately 300 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.
Cerium is has a hardness of approximately 2.5.
See also: Hardness of Materials
Cerium – Crystal Structure
A possible crystal structure of Cerium is double 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 Cerium
Thermal Properties of Cerium
Cerium – Melting Point and Boiling Point
Melting point of Cerium is 798°C.
Boiling point of Cerium is 3457°C.
Note that, these points are associated with the standard atmospheric pressure.
Cerium – Thermal Conductivity
Thermal conductivity of Cerium 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 Cerium
Linear thermal expansion coefficient of Cerium is 6.3 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.
Cerium – Specific Heat, Latent Heat of Fusion, Latent Heat of Vaporization
Specific heat of Cerium is 0.19 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 Cerium is 5.46 kJ/mol.
Latent Heat of Vaporization of Cerium is 414 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.
Cerium – 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 Cerium
Electrical resistivity of Cerium is 828 nΩ⋅m.
Electrical conductivity and its converse, electrical resistivity, is a fundamental property of a material that quantifies how Cerium conducts the flow of electric current. Electrical conductivity or specific conductance is the reciprocal of electrical resistivity.
Magnetic Susceptibility of Cerium
Magnetic susceptibility of Cerium is +2450e-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 Cerium in response to an applied magnetic field.
Application and prices of other elements