Yttrium has the highest thermo-dynamic affinity for oxygen of any element, this characteristic is the basis for many of its applications. While not part of the rare earth series, it resembles the heavy rare earths which are often referred to as the yttrics.
Another unique characteristic derives from its ability to form crystals with useful properties.
Many other applications of yttrium include roles in ceramics for crucibles for molten reactive metals, in florescent lighting phosphors, computer displays and automotive fuel consumption sensors.
Yttria stabilized zirconium oxide are used not only in high temperature applications, such as in thermal plasma sprays to protect aerospace high temperature surfaces, but also in abrasion resistant milling materials as milling media and jars.
Crystals of the yttrium-iron-garnet (YIG) variety are essential to microwave communication equipment.
The phosphor Eu:Y2O2S creates the red color in televisions.
Crystals of the yttrium-aluminum-garnet (YAG) variety are utilized with neodymium in a number of laser applications.
Yttria can also increase the strength of metallic alloys.