Yttrium oxides are a component of the phosphors used to produce the red color in television picture tubes. The oxides have potential use in ceramics and glass. Yttrium oxides have high melting points and impart shock resistance and low expansion to glass. Yttrium iron garnets are used to filter microwaves and as transmitters and transducers of acoustic energy. Yttrium aluminum garnets, with a hardness of 8.5, are used to simulate diamond gemstones. Small quantities of yttrium may be added to reduce the grain size in chromium, molybdenum, zirconium, and titanium, and to increase the strength of aluminum and magnesium alloys. Yttrium is used as a deoxidizer for vanadium and other nonferrous metals. It is used as a catalyst in the polymerization of ethylene.
Basic Facts About Yttrium
Atomic Number: 39
Atomic Weight: 88.90585
Discovery: Johann Gadolin 1794 (Finland)
Electron Configuration: Kr 5s1 4d1
Word Origin: Named for Ytterby, a village in Sweden near Vauxholm. Ytterby is the site of a quarry which yielded many minerals containing rare earths and other elements (erbium, terbium, and ytterbium).
Isotopes: Natural yttrium is composed of yttrium-89 only. 19 unstable isotopes are also known.
Properties: Yttrium has a metallic silver luster. It is relatively stable in the air except when finely divided. Yttrium turnings will ignite in air if their temperature exceeds 400°C.
Yttrium Physical Data
Element Classification: Transition Metal
Density (g/cc): 4.47
Melting Point (K): 1795
Boiling Point (K): 3611
Appearance: silvery, ductile, moderately reactive metal
Atomic Radius (pm): 178
Atomic Volume (cc/mol): 19.8
Covalent Radius (pm): 162
Ionic Radius: 89.3 (+3e)
Specific Heat (@20°C J/g mol): 0.284
Fusion Heat (kJ/mol): 11.5
Evaporation Heat (kJ/mol): 367
Pauling Negativity Number: 1.22
First Ionizing Energy (kJ/mol): 615.4
Oxidation States: 3
Lattice Structure: hexagonal
Lattice Constant (Å): 3.650
Lattice C/A Ratio: 1.571
Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Lange's Handbook of Chemistry (1952), CRC Handbook of Chemistry & Physics (18th Ed.)