Holmium(III) oxide

Holmium

Yellowish solid

Fixed

8.4 g · cm -3

2330 ° C

3900 ° C

Insoluble in water

Template: Infobox chemical / molecular formula search available

Holmium (III ) oxide is a chemical compound selected from the group of the oxides.

History

1878 discovered the Swiss chemist Marc Delafontaine and Jacques -Louis Soret, the element holmium spectroscopically by its different absorption lines. Discovered in 1879, the Swedish chemist Per Teodor Cleve the new element independently of the two Swiss and isolated it as a yellow oxide from impure erbium oxide. Cleveland turned to a technology developed by Carl Gustav Mosander method; First he separated from all known contaminants before he tried to separate the rest. He received a brown residue, which he called Holmia, as well as a green residue which was named Thulia.

It was not until 1911 managed the Swedish chemist Holmberg the recovery of pure holmium.

Occurrence

Holmium (III ) oxide occurs naturally in trace amounts in the minerals Gadolinit, monazite and other Seltenerdmineralien ago.

Production and representation

Holmium (III ) oxide is formed in the oxidation of holmium:

It can also be obtained by thermal decomposition of Holmiumsalzen as Holmiumnitrat.

Properties

Holmium (III ) oxide is a yellowish solid which is insoluble in water. It reacts with acids forming cations, which in turn react weakly acidic in water.

Use

Holmium (III ) oxide is used as an additive in glass for optical filters, as it shows a strong absorption in the narrow frequency bands in the visible and UV light. It is also used in the manufacture of metal halide lamps.