Scandium

Scandium (Sc), chemical symbol Sc, atomic number 21, is a soft, silvery transition metal classified as one of the rare earth elements. Scandium has an atomic weight of 44.955908 u. It has a melting point of 1541°C (2806°F) and a boiling point of 2836°C (5137°F), with a density of 2.985 g/cm3. Although scandium is sparsely distributed in the earth's crust, its abundance is higher than lead and mercury. Due to its rarity and high cost, the applications of scandium are limited to some specialized areas.

In electronics and semiconductors, scandium finds use as a dopant material to improve the characteristics of high-performance solid-state devices. Scandium-doped gallium nitride (GaN:Sc) can influence the semiconductor's electronic structure, enhancing its optoelectronic properties which are critical for light-emitting diodes (LEDs) and laser diodes (LDs). Additionally, scandium can be utilized to make specific alloys, combined with aluminum to form Sc-Al alloys used in aerospace materials to improve the performance of aircraft and spacecraft. 

While not as ubiquitous as some other elements, scandium's unique properties enable it to play an important role in certain high-tech fields like the R&D of advanced electronics and semiconductor devices. Its scarcity and difficulty of extraction also spur scientists and engineers to seek more economical substitute materials. And, scandium is also consumed as sputter targets in R&D fields.