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Europium Compounds
Europium compounds are compounds formed by the lanthanide metal europium (Eu). In these compounds, europium generally exhibits the +3 oxidation state, such as EuCl3, Eu(NO3)3 and Eu(CH3COO)3. Compounds with europium in the +2 oxidation state are also known. The +2 ion of europium is the most stable divalent ion of lanthanide metals in aqueous solution. Many europium compounds fluoresce under ultraviolet light due to the excitation of electrons to higher energy levels. Lipophilic europium complexes often feature acetylacetonate-like ligands, e.g., Eufod. Properties of europium compounds Chalcogenides Oxides Europium(II) oxide can be obtained by the reduction of europium(III) oxide with metallic europium at high temperatures. It has a rock-salt structure, is a deep red solid, and is ferromagnetic at 77 K. It has the potential to become a magnetic refrigeration material (ΔSmag=−143 mg/cm3 K，50 kOe).无机化学丛书. pp 200-203. 2. 氧族化合物; pp 215. 3. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luminescence Of Europium Compounds
Luminescence is spontaneous emission of light by a substance not resulting from heat; or "cold light". It is thus a form of cold-body radiation. It can be caused by chemical reactions, electric potential energy, electrical energy, subatomic motions or piezoelectricity, stress on a crystal. This distinguishes luminescence from incandescence, which is light emitted by a substance as a result of heating. Historically, radioactive decay, radioactivity was thought of as a form of "radio-luminescence", although it is today considered to be separate since it involves more than electromagnetic radiation. The dials, hands, scales, and signs of aviation and navigational instruments and markings are often coated with luminescent materials in a process known as "luminising". Types The following are types of luminescence: *Chemiluminescence, the emission of light as a result of a chemical reaction **Bioluminescence, a result of biochemical reactions in a living organism **Electrochemilumines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
