Introduction
Europium (atomic number 63) is the most reactive of all rare earth elements. It is a Heavy Rare Earth Element (sometimes classified as medium) and is famous for its role in bringing color to the world through television and modern lighting.
Chemical & Physical Properties
Europium is a ductile metal with a hardness similar to lead. It is extremely reactive; it oxidizes almost immediately in air and reacts vigorously with water, similar to calcium. It must be stored under inert oil or in a vacuum.
Occurrence & Production
It is one of the rarest of the common REEs. It is found in monazite and bastnäsite, but ion-adsorption clays in southern China are a significant source.
Key Applications & Uses
- Phosphors (Red and Blue): Europium is unparalleled in its ability to create phosphors.
- Europium oxide (Eu2O3) is the primary activator for red phosphors in CRT televisions (historically) and currently in fluorescent lamps and white LEDs.
- Divalent Europium creates blue phosphors.
- Virtually all energy-efficient lighting relies on Europium to create a warm, balanced white light.
- Anti-Counterfeiting: Used in phosphorescent marks on Euro banknotes and other currencies that glow under UV light to prevent forgery.
Future Outlook & Significance
Despite the shift away from CRT screens, Europium is absolutely essential for low-energy lighting (LEDs and CFLs). Its unique electronic structure makes it difficult to replace as a red phosphor source.