Ytterbium

History

Occurence

• Ytterbium occurs along with other rare earths in a number of rare minerals.
• It is commercially recovered principally from monazite sand, which contains about 0.03%.
• Ion-exchange and solvent extraction techniques developed in recent years have greatly simplified the separation of the rare earths from one another.
• The element was first prepared by Klemm and bonner in 1937 by reducing ytterbium trichloride with potassium.
• Their metal was mixed, however, with KCl.
• Daane, Dennison, and Spedding prepared a much purer from in 1953 from which the chemical and physical properties of the element could be determined.

Properties

• Ytterbium has a bright silvery luster, is soft, malleable, and quite ductile.
• While the element is fairly stable, it should be kept in closed containers to protect it from air and moisture.
• Ytterbium is readily attacked and dissolved by dilute and concentrated mineral acids and reacts slowly with water.
• Ytterbium has three allotropic forms with transformation points at -13C and 795C.
• The beta form is a room-temperature, face-centered, cubic modification, while the high-temperature gamma form is a body-centered cubic form.
• Another body-centered cubic phase has recently been found to be stable at high pressures at room temperatures.
• The beta form ordinarily has metallic-type conductivity, but becomes a semiconductor when the pressure is increased about 16,000 atm.
• The electrical resistance increases tenfold as the pressure is increased to 39,000 atm and drops to about 10% of its standard temperature-pressure resistivity at a pressure of 40,000 atm.

Isotopes

Uses

• Ytterbium metal has possible use in improvind the grain refinement, strength, and other mechanical properties of stainless steel.
• One isotope is reported to have been used as a radiation source as a substitute for a portable X-ray machine where electricity is unavailable.
• Few other uses have been found.

Availability