Europium is utilized primarily for its unique luminescent behavior. Excitation of the europium atom by absorption of ultra violet radiation can result in specific energy level transitions within the atom creating an emission of visible radiation. In energy efficient fluorescent lighting, europium provides not only the necessary red, but also the blue. Several commercial blue phosphors are based on europium. Its luminescence is also valuable in medical, surgical and biochemical applications.

Europium is available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultra-high purity). Elemental or metallic forms include pellets, rod, wire and granules for evaporation source material purposes. Europium oxide is available in powder and dense pellet form for such uses as optical coating and thin film applications. Oxides tend to be insoluble. Europium fluorides are another insoluble form for uses in which oxygen is undesirable such as metallurgy, chemical and physical vapor deposition and in some optical coatings. Europium is also available in soluble forms including chlorides, nitrates and acetates. These compounds can be manufactured as solutions at specified stoichiometries.

Single crystals of rare-earth acetate-hydrates M(OAc)₃(H2O)_x (OAc =acetate) are quite easily obtained from aqueous solutions by isothermal evaporation of the solvent water. Crystal structures were determined for hydrates with x  1, 1.5, 3, and 4. As the relatively large trivalent rare-earth cations afford coordination numbers of at least six and up to twelve, the individual coordination polyhedra which consist of one- or bidentate acetate ions and water molecules, need to be connected.

Anhydrous europium(III) acetate, Eu(OAc)₃ crystallizes isotypically with Ho(OAc)3. Eu(OAc)₃ (1, monoclinic, C2/c) undergoes a phase transition to the higher symmetrical structure of Sc(OAc)₃ (hexagonal, P63/mcm) at 181 °C and decomposes at 339 °C. Single crystals of the anhydrous europium(III) acetate are obtained by direct oxidation of europium metal with anhydrous acetic acid at 130 °C in a sealed glass ampoule.

Europium(III) Acetate Hydrate is a moderately water soluble crystalline Europium source that decomposes to Europium oxide on heating. It is generally immediately available in most volumes. All metallic acetates are inorganic salts containing a metal cation and the acetate anion, a univalent (-1 charge) polyatomic ion composed of two carbon atoms ionically bound to three hydrogen and two oxygen atoms (Symbol: CH3COO) for a total formula weight of 59.05.