Definition of "yttrium" []

• A silvery metallic element, not a rare earth but occurring in nearly all rare-earth minerals, used in various metallurgical applications, notably to increase the strength of magnesium and aluminum alloys. Atomic number 39; atomic weight 88.906; melting point 1,522°C; boiling point 3,338°C; specific gravity 4.45 (25°C); valence 3. See Table at element. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "A material called yttrium barium copper oxide can be turned into a superconductor by exposure to liquid nitrogen - which makes it one of the highest-temperature superconductors."
• "The development project with mine-owner Wings Enterprises Inc. comes as concerns heighten about China's tight grip on production of metals such as yttrium required in hybrid vehicles, wind turbines, flat panel televisions, defense missiles and satellites."
• "Solid oxide fuel cells typically require rare elements such as yttrium, zirconium, lanthanum, strontium or cesium, cerium, etc."