Europium(III) oxalate (Eu₂(C₂O₄)₃) is a

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

europium Europium is a chemical element; it has symbol Eu and atomic number 63. It is a silvery-white metal of the lanthanide series that reacts readily with air to form a dark oxide coating. Europium is the most chemically reactive, least dense, and soft ...

and

oxalic acid Oxalic acid is an organic acid with the systematic name ethanedioic acid and chemical formula , also written as or or . It is the simplest dicarboxylic acid. It is a white crystalline solid that forms a colorless solution in water. Its name i ...

. There are different

hydrate In chemistry, a hydrate is a substance that contains water or its constituent elements. The chemical state of the water varies widely between different classes of hydrates, some of which were so labeled before their chemical structure was understo ...

s including the decahydrate, hexahydrate and tetrahydrate. Europium(II) oxalate is also known.

Preparation

An excess of oxalate is added to a hot solution of Eu³⁺

cation An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...

s. The resulting

precipitate In an aqueous solution, precipitation is the "sedimentation of a solid material (a precipitate) from a liquid solution". The solid formed is called the precipitate. In case of an inorganic chemical reaction leading to precipitation, the chemic ...

of Eu₂(C₂O₄)₃ ⋅ 10H₂O is dried in a

desiccator Desiccators are sealable enclosures containing desiccants used for preserving moisture-sensitive items such as cobalt chloride paper for another use. A common use for desiccators is to protect chemicals which are hygroscopic or which react wit ...

Properties

Europium(III) oxide Europium is a chemical element; it has symbol Eu and atomic number 63. It is a silvery-white metal of the lanthanide series that reacts readily with air to form a dark oxide coating. Europium is the most chemically reactive, least dense, and sof ...

(Eu₂O₃) can be prepared by

calcining Calcination is thermal treatment of a solid chemical compound (e.g. mixed carbonate ores) whereby the compound is raised to high temperature without melting under restricted supply of ambient oxygen (i.e. gaseous O2 fraction of air), generally fo ...

europium(III) oxalate. The dehydration of Eu₂(C₂O₄)₃ · 10H₂O occurs below 200 °C: : The

decomposition Decomposition is the process by which dead organic substances are broken down into simpler organic or inorganic matter such as carbon dioxide, water, simple sugars and mineral salts. The process is a part of the nutrient cycle and is ess ...

of this compound takes place in two stages, the first at 350 °C and the second at about 620 °C. : In the Mössbauer spectrum, Eu₂(C₂O₄)₃ · 10H₂O shows an isomer shift of +0,26 mm/s with a line width of 2,38 mm/s, in reference to EuF₃. The

Debye temperature In thermodynamics and solid-state physics, the Debye model is a method developed by Peter Debye in 1912 to estimate phonon contribution to the specific heat (heat capacity) in a solid. It treats the oscillation, vibrations of the Crystal struct ...

of Eu₂(C₂O₄)₃ is 166±15 K. Eu₂(C₂O₄)₃ · 10H₂O crystallizes monoclinically in the space group of ''P21/c'' (space group no. 14) with the lattice parameters ''a'' = 1098, '' b'' = 961, ''c'' = 1004 pm and ''β'' = 114.2° with four formula units per unit cell.

Nanoparticle A nanoparticle or ultrafine particle is a particle of matter 1 to 100 nanometres (nm) in diameter. The term is sometimes used for larger particles, up to 500 nm, or fibers and tubes that are less than 100 nm in only two directions. At ...

s show a line emission when excited by a light source of 393 nm, the transitions ⁵D₀→⁷F₁ (592 nm) and ⁵D₀→⁷F₂ (616 nm) can then be found in the spectrum. This can be used as a red

phosphor A phosphor is a substance that exhibits the phenomenon of luminescence; it emits light when exposed to some type of radiant energy. The term is used both for fluorescent or phosphorescent substances which glow on exposure to ultraviolet or ...

for white

LED A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (corresp ...

References

{{Oxalates Europium(III) compounds Oxalates