Terbium

Description

Terbium is primarily used in phosphors, particularly in fluorescent lamps and as the high intensity green emitter used in projection televisions, such as the yttrium-aluminum-garnet (Tb:YAG) variety. Terbium responds efficiently in x-ray excitation and is, therefore, used as an x-ray phosphor. Terbium alloys are also used in magneto-optic recording films, such as Tb-Fe-Co. A variety of terbium-doped compounds can act as phosphors for use in television screens, other displays, lighting, or sensors.

Most notably, terbium green phosphors are used in trichromatic fluorescent lamps along with europium blue and red phosphors to produce white light with greater energy efficiency than incandescent lighting. In zirconia oxide ceramics, terbium can act both as a light-emitting dopant and a crystal stabilizer, producing a material with excellent structural and optical properties. Other terbium doped compounds have useful electrical properties that make them potentially useful in the semiconductor industry.

Terfenol-D is an alloy of terbium, iron, and dysprosium that is magnetostrictive: it contracts or expands when exposed to magnetic fields. This property allows direct conversion between electrical and mechanical power, and the alloy is used in sensors, actuators, and acoustic and ultrasonic transducers, and active noise and vibration cancelling devices. Terbium is available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultrahigh purity); metals in the form of foil, sputtering target, and rod, and componds as submicron and nanopowder.

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