Terbium Oxide (Tb₄O₇; MW 747.7 g/mol) is a mixed-valence rare earth oxide — formally terbium(III,IV) oxide — presenting as a dark brown to brown-black powder with a density of 7.3 g/mL at 25 °C and negligible water solubility. It is commercially available in Technical and Electronic Grades at purities of 99.9–99.99 % on a Tb₄O₇/TREO basis, with TREO ≥ 99 %.
Its principal industrial function is as a green phosphor activator in display and lighting applications, where terbium's characteristic 4f-electron transitions produce high-efficiency green emission. The compound also serves as a coercivity-enhancing additive in NdFeB permanent magnet alloys and as a precursor to terbium metal and downstream terbium compounds used in magnetostrictive and magneto-optical materials.
Terbium Oxide
Applications
- Electronics & Solar PV: Primary activator in green-emitting phosphors for fluorescent lamps, LED phosphor blends, and flat-panel display backlighting systems.
- Electronics & Solar PV: Incorporated into magneto-optical glass formulations where high Verdet constants are required for Faraday rotators and optical isolators.
- Automotive: Added to NdFeB sintered magnet alloys as a coercivity-enhancing dopant, improving high-temperature performance in traction motor magnets.
- Electronics & Solar PV: Used in the production of Terfenol-D (terbium–dysprosium–iron) magnetostrictive alloys for precision actuators and sonar transducers.
- Electronics & Solar PV: Serves as a high-purity oxide precursor for the synthesis of terbium metal, terbium fluoride, and other downstream terbium compounds.
Safety & Risks
Not classified as hazardous under GHS. Handle as a fine inorganic powder: use dust mask (N95), safety glasses, and gloves. Store in a cool, dry location in sealed containers away from moisture.
Packaging
Supplied in 1–5 kg sealed containers for Electronic Grade lots; 25 kg fiber or iron drums for Technical Grade. Store sealed, away from moisture.