Scandium (Sc, atomic number 21) is a rare earth element with atomic weight 44.955908. Its melting point is 2,806°F (1,541°C). The appearance of its metal form is silvery-white while slightly yellowish or pinkish cast when oxidized in air. It can be dissolved slowly in most dilute acids. Similar to the early founded lanthan and yttrium, in the fullerene cluster, scandium shows as +3 metal cation and enables a new type of host/guest nanostructured material. Scandium is a soft transition metal and could be in various forms such as powder, solid metal (sputtering target, disc, rod, lump, plate), alloys (mainly Al-Sc alloy), chemical compounds. Scandium chemical compounds include scandium oxide, scandium chloride, scandium carbonate, scandium fluoride, scandium nitrate, etc.
Application of Scandium
As a component of alloy, scandium is used mainly in aluminum-scandium alloys. Addition of scandium improves the grain refinement of ingots and casting based on certain concentration of scandium. By increasing the recrystallization temperature, the aluminum alloys increase the weldability. It enables the alloys as strong as titanium, as light as aluminum and as hard as ceramic. When used in minor aerospace industry, 0.1% ~2% of scandium was contained in alloys. Aluminum-scandium alloy can also be used in sports equipment due to the physical characteristics.
Meanwhile, scandium is employed in the solid-state synthesis with other metals like Mn, Fe, Ru or Os to show the special magnetic properties.
In lightning areas, scandium iodide is one of the materials to make up metal halide lamp or light bulbs.
Scandium used in 400 nm Sc75Fe25 nanoglass exhibits excellent plastic deformation ability.
Scandium oxide exhibits ac conductivity at temperatures between 4 and 295 K. It is newly found that scandium borocarbide with a layered crystal structure performs superconductivity.
Scandium is named from Scandinavia, the place where it was found. The global scandium supply and consumption is about 10-15 tons/y though the resources are abundant.
The price in US maintains in a stable level in recent years as U.S. Geological Survey reported in 2019, while in China the raw scandium oxide holds a relatively low price.
In worldwide, exploration continues to meet the increased demand, though the scandium market remains relatively small compared to other metals. Several projects are undergoing to enable the new aluminum-scandium alloys commercialized as casting and addictive in manufacturing industry.
Future of scandium
With high melting temperature, high conductivity, good flexibility in compound, scandium will be a candidate in functional materials. It will also be used in healthcare region as it has not been found toxic, though ranges of animal testing should be done in the future.