Annual world production (2022)
Gadolinium oxide
Phosphor and material for superconductorsWhat is gadolinium oxide?
Gadolinium is a silvery-white, soft, highly malleable heavy metal, with compact gadolinium looking very similar to iron. This heavy rare earth was discovered by the Swiss scientist Jean Charles Galissard de Marignac in 1880. However, gadolinium was named after the Finnish chemist Johann Gadolin, who had discovered the first rare earth, namely yttrium. The mineral gadolinite, which is rich in rare earths, was also named after him. Gadolinium was not isolated and produced in pure form until 1886.
Gadolinium oxide has a wide range of applications in technology and medicine. Its best-known use is as a contrast agent in magnetic resonance imaging (MRI). Here, gadolinium plays a crucial role in the diagnosis of tumors. Due to its high neutron absorption, gadolinium oxide is also used to manufacture control rods in nuclear reactors as well as for radiation shielding applications. This rare earth is also used in iron, chromium and steel alloys.
Price Development
A renaissance of nuclear power can currently be observed in many countries. This could contribute to rising gadolinium prices. The metal is also still indispensable for medical imaging procedures. This, too, could lead to price increases due to the scarcity of this rare earth.
Main Applications
- Microwave applications
- Radar technology
- Contrast agents in MRI scanners
- Magneto-optical data storage
- Refrigeration equipment
- X-ray technology
Facts about gadolinium oxide
annual global production volume
Modern data storage relies on gallium-gadolinium garnet
A material known as gallium-gadolinium garnet offers excellent optical as well as mechanical and thermal properties. The artificially grown crystals are used in data storage in the form of magneto-optical films (bubble memory), and also in the manufacture of laser components.
In addition, the crystals are used in cryogenics, when objects are cooled to temperatures close to absolute zero.
Mining and extraction
The lanthanoid gadolinium ranks 45th in terms of elemental abundance and is therefore one of the rarer elements on the planet. In fact, its share in the Earth’s crust is around 6.2 parts per million (ppm). Gadolinium is almost always found together with other rare earths, especially in monazite sands and minerals of the yttrium rare earths, such as xenotime. Gadolinium deposits occur along the coasts of Australia, Brazil and India, but the most important producer, as with the other rare earths, is China.
To obtain gadolinium, the ore is first concentrated and then digested. The resulting lanthanoid oxide mixture is then converted into chlorides or fluorides. These are then separated by cation exchange or solvent extraction. The gadolinium metal is then obtained by reducing the resulting salts (halides) with calcium under vacuum.
Growth Markets
- Microwave applications
- Radar technology
- Contrast agents in MRI scanners
- Magneto-optical data storage
- Refrigeration equipment
- X-ray technology
- Control rods for nuclear reactors
- Steel and iron alloys
- Phosphors
Interesting fact:
Materials science is interested in gadolinium oxide because of an unusual property: the heavy metal has negative thermal expansion, which means that in certain temperature ranges it contracts when heated instead of expanding. This rare property makes gadolinium and its compounds interesting for materials science and engineering, especially in the development of materials that must remain stable under varying temperature conditions.
