- Neodymium (Nd) is a hard, silvery metal with atomic number 60, belonging to the lanthanide series of the periodic table.
- It has an electron configuration of [Xe] 4f⁴ 6s² and typically loses three electrons to form the Nd³⁺ ion, its most stable oxidation state. Its atomic structure contains sixty protons, generally eighty-four or eighty-six neutrons, and sixty electrons arranged in six shells.
- Naturally occurring neodymium consists of seven stable isotopes, with neodymium-142 (¹⁴²Nd) being the most abundant at about 27.2%, followed by ¹⁴⁴Nd, ¹⁴⁶Nd, ¹⁴⁸Nd, and others.
- Neodymium is never found in its pure metallic state but occurs in various rare earth minerals, especially monazite ((Ce,La,Nd,Th)PO₄) and bastnäsite ((Ce,La)(CO₃)F). These minerals, mined primarily in China, the United States, Brazil, and Australia, also contain other lanthanides, making separation a chemically intensive process.
- The element was discovered in 1885 by Austrian chemist Carl Auer von Welsbach, who separated it from “didymium,” a substance previously thought to be a single element. The name “neodymium” comes from the Greek neos didymos, meaning “new twin,” reflecting its close relationship with praseodymium, from which it was isolated.
- Neodymium’s most famous and commercially significant use is in the production of high-strength permanent magnets—specifically neodymium–iron–boron (Nd₂Fe₁₄B) magnets. These are among the strongest known permanent magnets and are widely used in electric motors, computer hard drives, wind turbines, cordless tools, and various electronic devices. Neodymium is also used in specialized glassmaking, where neodymium oxide produces distinctive purple, violet, or wine-red tints. These glasses are used in welding goggles, decorative glassware, and astronomical instruments. In lasers, neodymium-doped crystals such as Nd:YAG (neodymium-doped yttrium aluminum garnet) produce highly coherent infrared light for industrial machining, medical surgery, and military applications.
- Chemically, neodymium is reactive and tarnishes in air, forming an oxide layer that can flake off, exposing more metal to oxidation. It reacts slowly with water and more rapidly with acids, releasing hydrogen gas. It readily forms ionic compounds in the +3 oxidation state, although +2 compounds are known but less stable.
- Biologically, neodymium has no known essential role in human metabolism. Most compounds are considered to have low toxicity, but inhalation of fine dust or ingestion of soluble neodymium salts can be harmful.
- Environmentally, neodymium in mineral form is relatively inert, but its extraction and refining from rare earth ores can have significant ecological impacts, including chemical waste and radioactive by-products from thorium-containing minerals.
