Yttrium
Yttrium is a chemical element with symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and it has often been classified as a "rare earth element". Yttrium is almost always found combined with the lanthanides in rare earth minerals and is never found in nature as a free element.
Identity
- Atomic mass
- 88.906 u
- Category
- Transition metals
- Group
- 3
- Period
- 5
- Block
- d
- Oxidation States
- +3
- Phase (25 °C)
- Solid
- Appearance
- silvery white
Electronic Structure
- Electron configuration
- 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d1
- Short configuration
- [Kr] 4d1 5s2
- Electrons per shell
- 2, 8, 18, 9, 2
- Electronegativity (Pauling)
- 1.22
- Electron affinity
- 29.6 kJ/mol
- 1st ionization energy
- 600 kJ/mol
- Ionization energies
- 600 · 1180 · 1980 · 5847 · 7430… kJ/mol
Physical properties
- Melting point
- 1525.8 °C (1799 K)
- Boiling point
- 2929.8 °C (3203 K)
- Density
- 4.472 g/cm³
- Molar heat capacity
- 26.5 J/(mol·K)
Chemical behavior of yttrium
Yttrium is a group 3 transition metal with symbol Y and atomic number 39. It is a silvery-white metal, chemically similar to scandium and the lanthanides. Its dominant oxidation state is +3. Its chemistry is closely tied to rare-earth elements with which it co-occurs.
Reactivity
2 Y + 3 Cl2 -> 2 YCl3
Yttrium reacts with chlorine forming yttrium(III) chloride, a white solid that is the precursor of many yttrium compounds.
2 Y + 3 H2O (hot) -> 2 Y(OH)3 + 3 H2
Yttrium reacts with steam at high temperatures, releasing hydrogen and forming yttrium hydroxide.
Notable compounds
| Compound | Formula | Use or importance |
|---|---|---|
| Yttrium(III) chloride | YCl3 | White solid; precursor of compounds and catalyst |
| Yttrium oxide | Y2O3 | White solid; used in lasers, fluorescence and ceramics |
| Yttrium aluminium garnet | YAG (Y3Al5O12) | High-hardness crystal; used in ray lasers and optoelectronic materials |
Electron shell distribution
View in the atom builderIsotopes
Natural yttrium is a single stable isotope: yttrium-89 (100 %). Radioisotopes include yttrium-90, a fission product with a 64-hour half-life used in targeted radiotherapy, and yttrium-86 for PET imaging research.
Occurrence and production
Trace crustal element (about 30 ppm) in gadolinite, xenotime and phosphate minerals, always with lanthanides. It is recovered from rare-earth processing. Main reserves are in China, Australia, India and Brazil.
History and origin of the name
Johan Gadolin found yttria in 1794 in a mineral from Ytterby, Sweden. The village gave its name to yttrium, ytterbium, terbium and erbium. Yttrium was the first rare-earth element recognized and its study opened the lanthanide field.
Applications and relevance of yttrium
Uses of the element
Used in Nd:YAG lasers, red phosphors for LEDs and displays, high-temperature superconductors, technical ceramics, radiation sensors and specialty alloys that resist high-temperature oxidation.
Uses of its compounds
YAG hosts laser ions; yttria stabilizes zirconia ceramics and fuel-cell electrolytes; orthophosphates and silicates serve in displays and scintillation detectors.
Health, safety and environment
Biological role
Yttrium is not essential for life. Inorganic compounds can be toxic in high doses. Dust irritates skin and airways; yttrium-90 for medicine is handled in sealed clinical systems, not everyday materials.
Safety
Metal is fairly stable but fine powder is flammable. Industrial work needs ventilation and respiratory protection. Waste goes to authorized facilities; medical isotopes require radiological control.
Environment
A critical high-tech material whose mining and separation from rare earths generate waste. Efficient use, long-lived products and recycling of lasers, phosphors and ceramics reduce pressure on primary sources.
Frequently asked questions about Yttrium
Why does yttrium appear in so many lasers?
Yttrium aluminium garnet (YAG) is a hard stable crystal that can host ions such as neodymium which emit laser light. Yttrium forms the framework holding the emitting ions. These lasers cut, weld and treat materials and serve in science and precision medicine.
How does yttrium help fuel cells?
Yttria stabilizes the zirconia electrolyte of solid-oxide fuel cells. The electrolyte must carry oxygen ions at high temperature without passing electrons. Yttria-stabilized zirconia does this, enabling electrochemical power. Thickness, temperature and composition set performance.
What links yttrium to X-ray cameras?
Some yttrium compounds are scintillators turning high-energy radiation into measurable flashes, such as cerium-activated lutetium-yttrium orthosilicate in detectors. Electronics then record signals for images or measurements.
Why is yttrium grouped with rare earths if it is not a lanthanide?
Because its size, +3 chemistry and ores match heavy lanthanides, so it travels with them in nature and industry. Plants separate them together. Historically it was the first rare-earth discovery, hence the lasting association.
Why is yttrium added to zirconia ceramics?
Yttria stabilizes crystal structures of zirconia and controls its transformations. Pure zirconia changes volume with phase changes and cracks; yttria-stabilized zirconia stays tough and stable. It is used in dental crowns, technical ceramics and electrochemical devices.
Why is yttrium in some superconductors?
YBCO (yttrium-barium-copper oxide) conducts without resistance below its critical temperature. It interests power, magnet and research technologies. But making and using it needs strict composition and conditions; yttrium alone makes nothing superconducting.
Why does yttrium appear in high-tech alloys?
Small additions can improve high-temperature behavior or oxidation resistance of metals, stabilize ceramic phases, or tune optical hosts. The effect depends on host material, concentration and processing; there is no universal function.
Main sources consulted: PubChem, Royal Society of Chemistry, NIST, IUPAC. Last revision: November 2026.