Europium(III) oxide (Eu 2 O 3 ), is a chemical compound of europium and oxygen . It is widely used as a red or blue phosphor in television sets and fluorescent lamps , and as an activator for yttrium -based phosphors. It is also an agent for the manufacture of fluorescent glass. Europium fluorescence is used in the anti-counterfeiting phosphors in Euro banknotes.
4-484: Europium oxide has two common structures: Monoclinic ( mS30 , space group C 2/ m , No. 12) and cubic ( cI80 , space group I a 3 , No. 206). The cubic structure is similar to that of manganese(III) oxide . It may be formed by ignition of europium metal. It can react with acids to form the corresponding europium(III) salts. This inorganic compound –related article is a stub . You can help Misplaced Pages by expanding it . Monoclinic In crystallography ,
8-647: A 2 + b 2 {\displaystyle {\frac {1}{2}}{\sqrt {a^{2}+b^{2}}}} of the conventional cell above. The table below organizes the space groups of the monoclinic crystal system by crystal class. It lists the International Tables for Crystallography space group numbers, followed by the crystal class name, its point group in Schoenflies notation , Hermann–Mauguin (international) notation , orbifold notation, and Coxeter notation, type descriptors, mineral examples, and
12-437: The monoclinic crystal system is one of the seven crystal systems . A crystal system is described by three vectors . In the monoclinic system, the crystal is described by vectors of unequal lengths, as in the orthorhombic system. They form a parallelogram prism . Hence two pairs of vectors are perpendicular (meet at right angles), while the third pair makes an angle other than 90°. Two monoclinic Bravais lattices exist:
16-414: The primitive monoclinic and the base-centered monoclinic. For the base-centered monoclinic lattice, the primitive cell has the shape of an oblique rhombic prism; it can be constructed because the two-dimensional centered rectangular base layer can also be described with primitive rhombic axes. The length a {\displaystyle a} of the primitive cell below equals 1 2
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