HOLMIO

Discovery

Holmium was discovered at Geneva in 1878 by Marc Delafontaine and Louis Soret, and independently by Per Teodor Cleve at Uppsala, Sweden. Both teams were investigating yttrium, which was contaminated with traces of other rare earths and had already yielded erbium which was later to yield ytterbium (go to these elements for further information). Cleve looked more closely at what remained after the ytterbium had been removed, and realised it must contain yet other elements because he found that its atomic weight depended on its source. He separated holmium from erbium in 1878. Delafontaine and Soret also extracted it from the same source, having seen unexplained lines in the atomic spectrum. We cannot be certain that either group had produced a pure sample of the new element because yet another rare-earth, dysprosium, was to be extracted from holmium. The pure metal was isolated in 1911 by Otto Holmberg

Uses

Holmium is found as a minor component of the minerals monazite and bastnaesite. It is extracted from those ores that are processed to extract yttrium. It is obtained by ion exchange and solvent extraction. Holmium can absorb neutrons, so it is used in nuclear reactors to keep a chain reaction under control. Its alloys are used in some magnets. Holmium has been used as a component of some electronic devices; the ion Ho³⁺ has been used as a catalyst for ortho-para hydrogen conversion; and the oxide has been used as a special refractory. Holmium is also used in solid-state lasers for non-invasive medical procedures treating cancers and kidney stones

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