Wohler obtained the impure element in 1828 by reduction of the anhydrous chloride with potassium. The metal is now produced commercially by reduction of the fluoride with calcium metal. It can also be prepared by other techniques. Yttrium has a silver-metallic luster and is relatively stable in air. Turnings of the metal, however, ignite in air if their temperature exceeds 400 deg C, and finely divided yttrium is very unstable in air.
Yttrium oxide is one of the most important compounds of yttrium and accounts for the largest use.
It is widely used in making YVO4 europium, and Y203 europium phosphors to give the red color in color television tubes. Many hundreds of thousands of pounds are now used in this application. Yttrium iron, aluminum, and gadolinium garnets, with formulas such as Y3Fe5O12 and Y3Al5O12, have interesting magnetic properties. Yttrium iron garnet is also exceptionally efficient as both a transmitter and transducer of acoustic energy. Alloys with other useful properties can be obtained by using yttrium as an additive.