Holmium
Element 67 · Lanthanide
Holmium is a soft, silvery metal that tarnishes slowly in air and is almost always +3 in compounds. Its record magnetic moment makes it the material of choice for the pole pieces that concentrate magnetic flux in the strongest laboratory magnets.
In medicine, holmium-doped YAG lasers cut tissue with remarkable precision in urology and orthopedic surgery. Holmium oxide glass, with its sharp absorption bands, is also the standard for calibrating spectrophotometers.
Key facts
| Atomic number | 67 |
|---|---|
| Atomic weight | 164.93 |
| Category | Lanthanide |
| Group / Period | — / 6 |
| Block | f |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f11 |
| Common oxidation states | +3 |
| State at STP | Solid |
| Electronegativity | 1.23 |
| Density | 8.79 g/cm³ |
| Melting point | 1474 °C |
| Boiling point | 2700 °C |
Occurrence
Holmium occurs in monazite, gadolinite, and xenotime, and is one of the scarcer lanthanides.
Applications
Ho:YAG surgical lasers
Magnetic pole pieces for strong magnets
Spectrophotometer calibration standards
High-strength magnets
Common compounds
- holmium oxide
- holmium chloride
Holmium is named after Holmia, the Latin name for Stockholm — and it holds the record for the highest magnetic moment of any element.
Data source: IUPAC standard atomic weights 2021