The rare earths are a group of 17 elements comprising the 15 lanthanide* elements (atomic numbers 57 through 71) plus scandium (Sc, 21) and yttrium (Y, 39). They are all chemically similar and always found together in mixed mineral ores. The name “rare” comes from the fact that these elements were discovered in a rare ore in Sweden in 1794, and “earth” refers to the fact that these elements occur as metal oxides with high melting points and are not easily reducible. In fact, we now know that yttrium, neodymium and some other rare earths occur in greater abundance than tin or cobalt. But because of the chemical similarity of the rare earths, sophisticated technologies are required for separation and refinement. Using proprietary technologies, Shin-Etsu has been producing high-purity rare earths from raw ore and supplying them to customers as oxides, metals and in other forms since 1967.

* Lanthanides: lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) and lutetium (Lu), although promethium does not occur naturally on earth.

Characteristics & Applications

Phosphors Yttrium and europium are used for red phosphors; terbium, lanthanum and cerium for green; and europium for blue. These phosphors are used to tri-color fluorescent lamp.They are also used in the backlights of LCD TVs, and in plasma and CRT TVs. Hydrogen storage Compared to other alloys, rare earth alloys have a faster hydrogen absorption and release rate, and reach equilibrium at lower pressure, making it possible to store hydrogen at room temperature. Magnetic materials Neodymium, samarium and cerium have outstanding properties as magnetic materials, enabling production of smaller, more powerful magnets. The high-tech sector Rare earths are also being used in a growing number of high-tech applications including cell phone components, fine ceramics, superconductors, and mini-discs (MD).