Atomic Number: 39
Atomic Symbol: Y
Atomic Weight: 88.90585
Melting Point: 2,772 F (1,522 C)
Boiling Point: 6,053 F (3,345 C)
Word origin: Yttrium is named after Ytterby, a village in Sweden near Vauxholm. There is a quarry in Ytterby that has yielded many unusual minerals containing rare earths and other elements. Because of this quarry, Ytterby has also been the namesake of erbium, terbium and ytterbium. [See Periodic Table of the Elements]
Discovery: Yttria — earth containing yttrium — was discovered in Ytterby’s quarry by Johan Gadolin in 1794. In 1843, Carl Gustaf Mosander demonstrated that yttria could be resolved into the oxides (or earths) of three elements. Yttrium was the most basic one. The others were named erbia and terbia.
Properties of yttrium
Yttrium (IT-ree-um) is a transition metal with a silvery luster. It is relatively stable in air. Turnings of the metal, however, ignite in the air if their temperature exceeds 400 C (752 F). Finely divided yttrium is very unstable in the air.
Sources of yttrium
Yttrium occurs in nearly all rare-earth minerals. Analysis of lunar rock samples obtained during the Apollo missions showed relatively high yttrium contents.
Friedrich Wohler obtained impure yttrium in 1828 by reduction of the anhydrous chloride and potassium. Yttrium is now commercially produced by reduction of the fluoride with calcium metal. It can also be prepared by other techniques. Yttrium is commercially recovered from monazite sand, which contains about 3 percent yttrium, and bastnasite, which contains about 0.2 percent yttrium.
Uses of yttrium
Yttrium and its compounds have a wide variety of uses. Yttrium oxide (Y2O3) accounts for the element’s largest use. The oxide, as well as yttrium vanadate (YVO4), is used with europium to make phosphors to create the red color in television tubes. Hundreds of thousands of pounds of yttrium oxide are used this way. It is also used to produce yttrium iron garnets, which are very effective microwave filters.
Yttrium iron, aluminum and gadolinium garnets, with formulas such as Y3Fe5O12 and Y3Al5O12, have useful magnetic properties. Yttrium iron garnet is exceptionally efficient as both a transmitter and transducer of acoustic energy. Yttrium aluminum garnet, with a hardness of 8.5, is sometimes used as a gemstone (substitute diamond).
Small amounts of yttrium (0.1 to 0.2 percent) can be used to reduce the grain size in chromium, molybdenum, zirconium and titanium, and to increase strength of aluminum and magnesium alloys. Alloys with other useful properties can be obtained by using yttrium as an additive. The metal can be used as a deoxidizer for vanadium and other nonferrous metals. It has a low cross section for nuclear capture. It has been considered for use as a nodulizer for producing nodular cast iron.
Yttrium can be used in laser systems and as a catalyst for ethylene polymerization reactions. It also has potential use in ceramic and glass formulas because as the oxide has a high melting point and imparts glass with shock resistance and low expansion characteristics.
Isotopes of yttrium
Natural yttrium contains one isotope, 89Y. Nineteen other unstable isotopes have been characterized. 90Y, one of the isotopes of yttrium, exists in equilibrium with its parent Strontium-90 (90Sr), a product of nuclear explosions.
(Source: Los Alamos National Laboratory)