Yttrium

Yttrium may be the element with the most difficult name to pronounce—although “ytterbium” and “praseodymium” are also in the running! The element is one of four named for the town of Ytterby, in Sweden, along with ytterbium, erbium, and terbium.

Yttrium owes its discovery to Carl Axel Arrhenius, a Swedish soldier and amateur chemist who, in 1787, discovered a strange black rock near an old quarry in Ytterby. Arrhenius determined that the rock was an unknown mineral, which he named ytterbite. In 1794, Johan Gadolin at the Royal Academy of Åbo identified a new oxide in Arrhenius’ mineral, calling it yttria. It was the first known rare-earth metal compound. Although the idea of a chemical element didn’t yet exist, Gadolin’s description of yttria, which contained yttrium, was so detailed that he gets credit for discovering element 39.

Yttrium has a silver color. It’s a soft, relatively stable metal, but small pieces can ignite at relatively low temperatures.

For decades, the most important use of yttrium was in cathode tubes, which gave televisions their color. Specifically, yttrium was used to produce a red color. However, because modern TVs don’t have cathode tubes, yttrium is used less often in this way.

Yttrium aluminum garnet is used to make artificial diamonds, and it’s also used in lasers. Scientists are also using yttrium in fuel cells, which can allow cars to run on fuels like hydrogen, instead of gasoline.

In recent years, yttrium has received a lot of attention as a superconductor. Superconductors are materials that don’t have electrical resistance, making them useful for applications like MRI machines. Superconductors need to be extremely cold to function, which limits their use and makes them expensive. It was a big deal when, in the 1980s, researchers discovered that yttrium barium copper oxide was a superconductor with a relatively high operating temperature.

Most yttrium used in commercial contexts is in the form of yttrium oxide. Yttrium oxide is used to make yttrium iron garnets, which are used to filter microwaves and for other electronics applications. Yttrium can also be added to metal alloys to make them better at resisting corrosion and oxidation.

In nature, yttrium is found exclusively in the form yttrium-89, its only stable (non-radioactive) isotope. At least 32 synthetic (laboratory-made) isotopes of yttrium have been observed. The least stable of these, yttrium-106, has a half-life of around 150 nanoseconds. A nanosecond is equal to one billionth of a second, so not much time at all! The most stable synthetic yttrium isotope, yttrium-88, has a half-life of around 107 days.

You’ll find yttrium in every rare-earth mineral. Commercially, most yttrium comes from monazite sands. India, Madagascar, and South Africa have major monazite sand deposits. In the past, Australia, Brazil, China, India, and the United States have all been major yttrium producers.