Yb - Ytterbium

Ytterbium is a soft, bright silvery metal that is also malleable and ductile. It is a member of the lanthanoid group of elements and is the 43rd most abundant element within the Earth’s crust. A protective layer forms on ytterbium’s surface, as when the pure metal is exposed to air, it slowly oxidises until it reaches a level where this oxide layer will protect it from further oxidisation. The metal reacts slowly with water and is dissolved readily in dilute acids.

History

Ytterbium was discovered by the French chemist, Jean de Marignac in 1878, and named it after Ytterby, which is a small village in Sweden responsible for the names of quite a few rare earth elements, and where the mineral used to extract ytterbium was found. Marignac was interested in erbium, which had been extracted from the element yttrium in 1843. Marignac was then able to extract a further 2 oxides from a sample of erbium nitrate he possessed, the first being erbium oxide and the second, he knew, must be the oxide of a new element. A sample of ytterbium metal was first made in 1937, although it was not pure enough for its properties to be reliably measured. It was not until 1953 that a pure sample was produced.

Sources

Commercially, ytterbium is extracted from monazite, which comprises of 0.1% ytterbium.  Other ores include euxenite, which is found in Greenland and Brazil, and xenotime.  The main mining areas are China, USA, Brazil, India, Sri Lanka and Australia, with global reserves estimated at around one million tonnes.  World production is approximately fifty tonnes per year.

Uses

There is little commercial application for Ytterbium, although the uses include strengthening stainless steel, doping phosphors in electronic devices and acting as an industrial catalyst.  One of ytterbium’s isotopes can be used as a portable radiation source as an alternative to an x-ray machine when electricity is not available.  Ytterbium salts are being introduced into the chemicals industry and catalysts in place of toxic and polluting ones.

Ytterbium has no biological role.  It is considered toxic, is a skin and eye irritant and a suspected thratogen.