Tb3

Tb3 refers to the terbium ion in the +3 oxidation state, i.e., the terbium(III) ion. Terbium is a lanthanide with atomic number 65, and the +3 state is its most stable and common form in both solution and solid compounds. In aqueous solution, Tb3+ forms aquated species and a variety of coordination complexes with ligands. Tb3+ is a hard Lewis acid, and stable coordination complexes typically have coordination numbers of 8 or 9, with water molecules or other ligands occupying coordination sites.

Occurrence and production: Terbium occurs naturally only in trace amounts in rare earth minerals such as monazite and bastnasite. It is recovered as a byproduct of processing these minerals and refined through solvent extraction, ion exchange, and related separation techniques to isolate Tb3+ from other lanthanides.

Chemistry: Tb3+ forms oxides such as Tb2O3 and hydroxides Tb(OH)3 at higher pH. It forms stable complexes with oxygen- and nitrogen-donor ligands—for example citrate and EDTA—and is widely used as a dopant in luminescent materials. In solid-state chemistry, Tb3+ doped phosphors are extensively used for green emission around 545 nm, arising from 4f–4f transitions.

Applications: Tb3+-doped materials are important in phosphors for lighting and display technologies, notably Y3Al5O12:Tb (YAG:Tb) and other hosts. They are also used as spectroscopic probes and in luminescent sensors for research purposes. Tb3+ salts appear in specialized imaging and analytical contexts as well.

Safety: Terbium compounds are generally considered to have low to moderate hazard potential; standard handling precautions for chemical powders and rare earth salts apply. Avoid inhalation and ingestion and follow appropriate disposal guidelines.