Holmium is a chemical element with the symbol Ho and atomic number 67. Part of the lanthanide series, holmium is a rare-earth element. It is the 67th element in the periodic table. This element belongs to the series of lanthanides in the periodic table. It has excellent stability at room temperature and is soluble in acids. The metal is highly affected by water and oxygen. It was discovered by a chemist J.L. Soret in the year 1878. It is a highly reactive metal when burnt in the presence of air.
Holmium is a paramagnetic as well as a ferromagnetic metal at a temperature below 19k. It appears as a bright and silver metal, and when it is oxidized, it forms an oxide which is yellowish in color. It has about one natural isotope and out of its synthetic isotopes, one is holmium-163 and it has a half-life of about 4570 years.
- It is a relatively soft and malleable element that is fairly corrosion-resistant and stable in dry air at standard temperature and pressure. In moist air and at higher temperatures, however, it quickly oxidizes, forming a yellowish oxide. In pure form, holmium possesses a metallic, bright silvery luster.
- Holmium oxide has some fairly dramatic color changes depending on the lighting conditions. In daylight, it has a tannish yellow color. Under trichromatic light, it is fiery orange-red, almost indistinguishable from the appearance of erbium oxide under the same lighting conditions.
- It has the highest magnetic moment (10.6 µB) of any naturally occurring element and possesses other unusual magnetic properties. When combined with yttrium, it forms highly magnetic compounds.
- It is paramagnetic at ambient conditions, but is ferromagnetic at temperatures below 19 K.
Uses of Holmium
- The alloys of Ho are used to create high magnetic fields in a magnetic flux concentrator.
- It is used as the control rods in nuclear reactors because of its high neutron capture cross-section.
- The oxides of this metal are used as a coloring agent in the glass.
- It is employed in optical spectrophotometers for the purpose of calibration.
- It also has a wide number of applications in the field of medical, fiber-optics, and in dental areas.