Yttrium is the chemical element with symbol Y and atomic number 39. It is a soft, silvery transition metal in group 3 and is commonly grouped with the rare-earth elements because it occurs with lanthanides in minerals and has similar chemistry.
Yttrium quick facts
| Property | Value |
| Symbol | Y |
| Atomic number | 39 |
| Relative atomic mass | 88.906 |
| Group | 3 |
| Period | 5 |
| Block | d-block |
| Density | 4.47 g/cm³ |
| Melting point | 1522°C |
| Boiling point | 3345°C |
| Electron configuration | [Kr] 4d¹ 5s² |
| Dominant oxidation state | +3 |
| CAS number | 7440-65-5 |
| Stable natural isotope | ⁸⁹Y |
Position and chemistry
Yttrium is in group 3, period 5 and the d-block. Its electron configuration is [Kr] 4d¹ 5s². Yttrium chemistry is dominated by the +3 oxidation state, and Y³⁺ resembles many trivalent lanthanide ions.
See the complete CleverlySmart periodic table.
Physical properties and occurrence
Yttrium is a soft, silvery metal that oxidises when exposed to air, especially when finely divided. It is found in minerals such as xenotime, monazite and bastnäsite and is separated from rare-earth mixtures through complex hydrometallurgical processes.
Important yttrium compounds
- Yttrium oxide (Y₂O₃): used in ceramics, phosphors, optical materials and high-temperature applications.
- Yttrium aluminium garnet (YAG): a durable optical crystal used as a laser host and in some LED phosphor systems.
- Yttrium barium copper oxide (YBCO): a famous high-temperature superconducting ceramic.
- Yttrium iron garnet (YIG): used in microwave, magneto-optical and communications technologies.
Uses of yttrium
- Lasers: Nd:YAG and other YAG-based lasers are used in manufacturing, medicine and research.
- LEDs and phosphors: yttrium-containing phosphors convert light into useful colours.
- Ceramics: yttria stabilises zirconia, improving toughness and high-temperature performance.
- Superconductors: YBCO can conduct electrical current with zero resistance below its critical temperature.
- Alloys: small yttrium additions can improve properties of magnesium and aluminium alloys.
Yttrium isotopes
Natural yttrium consists essentially of one stable isotope, ⁸⁹Y. The radioactive isotope ⁹⁰Y is a strong beta emitter used in targeted radiotherapy and radioembolisation for certain cancers under medical supervision.
For broader isotope information, see the CleverlySmart isotope table.
Biological role and safety
Yttrium has no known biological role. Soluble yttrium salts should be handled with normal chemical precautions, and fine yttrium powders can be a fire hazard. Radioactive yttrium requires specialised radiation controls.
Discovery and name
Yttrium was discovered through analysis of a mineral from Ytterby, Sweden, a village that also gave names to ytterbium, terbium and erbium. Johan Gadolin identified a new earth in 1794, and metallic yttrium was later isolated. The name reflects the mineral’s geographic origin.
Frequently asked questions
Is yttrium a rare-earth element?
It is a transition metal rather than a lanthanide, but it is conventionally included with the rare-earth elements because of its similar chemistry and mineral occurrence.
What is yttrium used for?
Major specialised uses include lasers, phosphors, ceramic materials, superconductors and electronic components.
Yttrium in lasers, ceramics and phosphors
Yttrium is widely used in materials where it improves thermal stability or optical performance. Yttrium aluminium garnet (YAG) is a durable crystal host for laser ions such as neodymium, while yttrium oxide and yttrium compounds are used in phosphors, advanced ceramics and specialised optical coatings.
Yttria-stabilised zirconia (YSZ) combines high-temperature strength with oxide-ion conductivity. It is used in oxygen sensors, thermal-barrier coatings and solid-oxide fuel cells.
Yttrium-90 in medicine
Radioactive yttrium-90 is a beta emitter used in selected medical treatments, including some forms of radioembolisation and targeted radiotherapy. These applications use controlled, clinically prepared radionuclides rather than ordinary stable yttrium metal.
Frequently asked questions
Is yttrium a lanthanide?
No. It sits in group 3 of the periodic table, but its chemistry resembles the heavier rare-earth elements and it commonly occurs with them in minerals.
Why is yttrium used in high-temperature ceramics?
Yttrium oxide can stabilise crystal structures and improve ionic conductivity and thermal performance.
