Thulium is an easily workable metal with a bright silvery-gray luster. It is fairly soft and slowly tarnishes in air. Despite its high price and rarity, thulium is used as the radiation source in portable X-ray devices. Thulium is the thirteenth and third-last element in the lanthanide series.
|Element category||Rare Earth Metal|
|Phase at STP||Solid|
|Ultimate Tensile Strength||N/A|
|Young’s Modulus of Elasticity||74 GPa|
|Brinell Hardness||470 MPa|
|Vickers Hardness||520 MPa|
|Melting Point||1545 °C|
|Boiling Point||1950 °C|
|Thermal Conductivity||17 W/mK|
|Thermal Expansion Coefficient||13.3 µm/mK|
|Specific Heat||0.16 J/g K|
|Heat of Fusion||16.84 kJ/mol|
|Heat of Vaporization||191 kJ/mol|
|Electrical resistivity [nanoOhm meter]||676|
|Magnetic Susceptibility||+25500e-6 cm^3/mol|
Applications of Thulium
The pure metal and compound have few commercial uses: because it is very rare and expensive and has little to offer, thulium find little application outside chemical research. Thulium has been used to create lasers. Thulium lasers require less cooling and function very well at high temperatures and are used in satellites. When stable thulium (Tm-169) is bombarded in a nuclear reactor it can later serve as a radiation source in portable X-ray devices. Thulium-170 is gaining popularity as an X-ray source for cancer treatment via brachytherapy. Thulium has been used in high-temperature superconductors similarly to yttrium. Thulium potentially has use in ferrites, ceramic magnetic materials that are used in microwave equipment. Thulium-doped calcium sulphate has been used in personal radiation dosimeters because it can register, by its fluorescence, especially low levels.
Production and Price of Thulium
Raw materials prices change daily. They are primarily driven by supply, demand and energy prices. In 2019, prices of pure Thulium were at around 70000 $/kg.
Thulium is principally extracted from monazite ores (~0.007% thulium) found in river sands, through ion exchange. 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. Approximately 50 tonnes per year of thulium oxide are produced.
Mechanical Properties of Thulium
Strength of Thulium
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 Thulium
Ultimate tensile strength of Thulium is N/A.
Yield Strength of Thulium
Yield strength of Thulium is N/A.
Modulus of Elasticity of Thulium
The Young’s modulus of elasticity of Thulium is N/A.
Hardness of Thulium
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 Thulium is approximately 470 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 Thulium is approximately 520 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.
Thulium is has a hardness of approximately N/A.
See also: Hardness of Materials
Thulium – Crystal Structure
A possible crystal structure of Thulium 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
Thermal Properties of Thulium
Thulium – Melting Point and Boiling Point
Melting point of Thulium is 1545°C.
Boiling point of Thulium is 1950°C.
Note that, these points are associated with the standard atmospheric pressure.
Thulium – Thermal Conductivity
Thermal conductivity of Thulium is 17 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 Thulium
Linear thermal expansion coefficient of Thulium is 13.3 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.
Thulium – Specific Heat, Latent Heat of Fusion, Latent Heat of Vaporization
Specific heat of Thulium is 0.16 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 Thulium is 16.84 kJ/mol.
Latent Heat of Vaporization of Thulium is 191 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.
Thulium – 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 Thulium
Electrical resistivity of Thulium is 676 nΩ⋅m.
Electrical conductivity and its converse, electrical resistivity, is a fundamental property of a material that quantifies how Thulium conducts the flow of electric current. Electrical conductivity or specific conductance is the reciprocal of electrical resistivity.
Magnetic Susceptibility of Thulium
Magnetic susceptibility of Thulium is +25500e-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 Thulium in response to an applied magnetic field.
Application and prices of other elements