Yttrium Y

Discovery

In 1787 Carl Axel Arrhenius, a Swedish army officer and amateur mineralogist, picked up an unusually heavy black mineral in a quarry at Ytterby, a village near Stockholm.

In 1794 the Finnish chemist Johan Gadolin found a new oxide in it, which came to be called yttria. The mineral itself was later named gadolinite in his honour.

Yttria was not pure. In 1843 Carl Gustaf Mosander separated the oxides of terbium and erbium from it, and over the following decades several more rare earths emerged from the same material. Friedrich Wöhler obtained impure yttrium metal in 1828.

Origin of the name

The element is named after Ytterby, the Swedish village whose quarry supplied the ore. Four elements take their names from that one village: yttrium, ytterbium, terbium and erbium. The symbol is Y.

Main uses

• White LEDs: cerium-doped yttrium aluminium garnet (YAG:Ce) phosphor converts part of the blue light from an LED chip into yellow, which together appear white.
• Lasers: neodymium-doped YAG crystals are workhorses of industrial cutting and medical lasers.
• Ceramics: yttria-stabilised zirconia is used in car oxygen sensors, fuel-cell electrolytes, thermal barrier coatings for jet engines and dental crowns.
• Superconductors: YBCO, discovered in 1987, superconducts at about 93 K, above the boiling point of liquid nitrogen, which caused great excitement.
• Older displays: europium-doped yttrium oxide produced the red colour in cathode-ray-tube televisions.

Isotopes

Yttrium has a single stable isotope, yttrium-89. Radioactive yttrium-90 is produced when strontium-90 decays and has a half-life of about 64 hours. Tiny beads loaded with yttrium-90 are injected into the arteries of the liver in a treatment called radioembolisation, which irradiates liver tumours from the inside.

In everyday life

Yttrium is extracted from rare earth minerals such as monazite and xenotime and from ion-adsorption clays in southern China. Small amounts are found in LED lamps, the backlights of screens, exhaust sensors and dental ceramics.

It has no known biological role, and ordinary exposure is of low concern. Inhaling dust of yttrium compounds can harm the lungs, however, so dust is controlled in industrial settings.