Yttrium is a silver-metallic, lustrous rare earth metal that is relatively stable in air and chemically resembles the lanthanides. Shavings or turnings of the metal can ignite in air when they exceed 400 °C. When yttrium is finely divided it is very unstable in air. The metal has a low cross section for nuclear capture. The common oxidation state of yttrium is +3.
Yttrium oxide is the most important yttrium compound and is widely used to make YVO4europium and Y2O3 europium phosphors that give the red color in color television picture tubes. Other uses;
Yttrium oxide is also used to make yttrium-iron-garnets which are very effective microwave filters.
Yttrium iron, aluminum, and gadolinium garnets (e.g. Y3Fe5O12 and Y3Al5O12) have interesting magnetic properties. Yttrium iron garnet is very efficient as an acoustic energy transmitter and transducer. Yttrium aluminum garnet has a hardness of 8.5 and is also used as a gemstone (simulated diamond).
Small amounts of the element (0.1 to 0.2%) have been used to reduce grain size of chromium, molybdenum, titanium, and zirconium. It is also used to increase the strength of aluminum and magnesium alloys.
This metal can be used to deoxidize vanadium and other nonferrous metals.
Yttrium has been studied for possible use as a nodulizer in the making of nodular cast iron which has increased ductility (the graphite forms compact nodules instead of flakes to form nodular cast iron). Potentially, yttrium can be used in ceramic and glass formulas, since yttrium oxide has a high melting point and imparts shock resistance and low expansion characteristics to glass.
In 1843Carl Mosander[?] was able to show that yttira could be divided into the oxides (or earths) of three different elements. "Yttria" was the name used for the most basic one and the others were named erbia and terbia.
A quarry is located near the village of Ytterby that yielded many unusual minerals that contained rare earths and other elements. The elements erbium, terbium, and ytterbium and yttrium have all been named after this same town.
This element is found in almost all rare earth minerals and in uranium ores but is never found in nature as a free element. Yttrium is commercially recovered from monazite sand (3% content, [(Ce, La, etc.)PO4) and from bastnasite (0.2% content, [(Ce, La, etc.)(CO3)F]). It is commercially produced by reducing yttrium fluoride with calcium metal but it can also be produced using other techniques. It is difficult to separate from other rare earths and when extracted, is a dark gray powder.
Lunar rock samples from the Apollo program have a relatively high yttrium content.
Natural yttrium is composed of only one isotope (Y-89). The most stable radioisotopes are Y-88 which has a half life of 106.65 days and Y-91 with a half life of 58.51 days. All the other isotopes have half lifes of less than a day except Y-87 which has a half life of 79.8 hours. The dominant decay mode below the stable Y-89 is electron capture and the dominant mode after it is beta emission. Twenty six unstable isotopes have been characterized.
Compounds that contain this element are rarely encountered by most people but should be considered to be highly toxic even though many compounds pose little risk. Yttrium salts may be cancerous. This element isn't normally found in human tissue and plays no known biological role.
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