Article · Wikipedia archive · Last revised Jun 17, 2026

Europium(III) oxide

Europium(III) oxide (Eu2O3), is a chemical compound of europium and oxygen. It is widely used as a red or blue phosphor in television sets and fluorescent lamps, and as an activator for yttrium-based phosphors. It is also an agent for the manufacture of fluorescent glass. Europium fluorescence is used in the anti-counterfeiting phosphors in Euro banknotes.

Last revised
Jun 17, 2026
Read time
≈ 2 min
Length
391 w
Citations
5
Source
Wikipedia ↗
Europium(III) oxide
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Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.013.787
UNII
  • InChI=1S/2Eu.3O checkY
    Key: RSEIMSPAXMNYFJ-UHFFFAOYSA-N checkY
  • InChI=1/2Eu.3O/rEu2O3/c3-1-5-2-4
    Key: RSEIMSPAXMNYFJ-NRICTGFVAC
  • O=[Eu]O[Eu]=O
Properties
Eu2O3
Molar mass 351.926 g/mol
Appearance white to light-pink solid powder
Odor odorless
Density 7.42 g/cm3
Melting point 2,350 °C (4,260 °F; 2,620 K)1
Boiling point 4,118 °C (7,444 °F; 4,391 K)
Negligible
+10,100·10−6 cm3/mol
Thermal conductivity 2.45 W/(m K)
Structure
cubic, cI80, Monoclinic
Ia-3, No. 206, C2/m, No. 12
Hazards
Lethal dose or concentration (LD, LC):
5000 mg/kg (rat, oral)
Safety data sheet (SDS) External MSDS
Related compounds
Other anions
 Europium(III) chloride
Other cations
 Samarium(III) oxide, Gadolinium(III) oxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Europium(III) oxide (Eu2O3), is a chemical compound of europium and oxygen. It is widely used as a red or blue phosphor in television sets and fluorescent lamps, and as an activator for yttrium-based phosphors. It is also an agent for the manufacture of fluorescent glass. Europium fluorescence is used in the anti-counterfeiting phosphors in Euro banknotes.2

Europium oxide has two common structures: Monoclinic (mS30, space group C2/m, No. 12)3 and cubic (cI80, space group Ia3, No. 206).4 The cubic structure is similar to that of manganese(III) oxide.

It may be formed by ignition of europium metal.5

It can react with acids to form the corresponding europium(III) salts.

  • Cubic Eu2O3
    Cubic Eu2O3
  • Monoclinic Eu2O3
    Monoclinic Eu2O3
References

References

  1. Webelements Europium trioxide
  2. "Europium and the Euro". Archived from the original on 2009-08-04. Retrieved 2009-06-04.
  3. "ICSD Entry: 631453". Cambridge Structural Database: Access Structures. Cambridge Crystallographic Data Centre. Retrieved 2022-07-04.
  4. Heiba, Z. K.; Akin, Y.; Sigmund, W.; Hascicek, Y. S. (2003). "X-ray structure and microstructure determination of the mixed sesquioxides (Eu1−xYbx)2O3 prepared by a sol–gel process". J. Appl. Crystallogr. 36 (6): 1411–1416. doi:10.1107/S0021889803019319.
  5. Ugale, Akhilesh; Kalyani, Thejo N.; Dhoble, Sanjay J. (2018). "Potential of europium and samarium β -diketonates as red light emitters in organic light-emitting diodes". Lanthanide-Based Multifunctional Materials. pp. 59–97. doi:10.1016/B978-0-12-813840-3.00002-8. ISBN 978-0-12-813840-3. Europium is the most reactive rare-earth element… It swiftly oxidizes in air, ignites in the range of 150–180°C to form Eu3+ oxide (Eu2O3).