Author:
Jan Scholten
Type:
Chapter:
13.0

13.0 Holmium physical

A trivalent metallic rare earth element, holmium has the highest magnetic moment (10.6┬ÁB) of any naturally-occurring element and possesses other unusual magnetic properties. When combined with yttrium, it forms highly magnetic compounds.
Holmium 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.

Atomic Number: 67.
Symbol: Ho.
Discovery: 1878 by P.T. Cleve at Uppsala, Sweden, and independently by M. Delafontaine and J.L. Soret at Geneva, Switzerland.
Name: Stockholm.
Toxicology: stimulates metabolism.
Ore: gadolinite, monazite.

Uses
1. Magnets: it has strong magnetic properties, holmium has been used to create the strongest artificially-generated magnetic fields when placed within high-strength magnets as a magnetic pole piece (also called a magnetic flux concentrator).
2. Super conducting magnets.
3. Laser: its very high magnetic moment is suitable for use in yttrium-iron-garnet (YIG) and yttrium-lanthanum-fluoride (YLF) solid state lasers found in microwave equipment (which are in turn found in a variety of medical and dental settings). YAl with Ho laser.
4. Holmium oxide is used as a yellow glass coloring.
5. Neutron absorption: in nuclear control rods for absorbing nuclear fission-bred neutrons.

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