Synthesis, crystal structures and luminescence properties of the Eu3+-doped yttrium oxotellurates(IV) Y2Te4O11 and Y2Te5O13

Phase formation and crystal structure determination in the Y2O3–TeO2 system prepared in an oxygen atmosphere

“…32 In addition to tellurite phases reported to appear in nitrogen atmosphere (Y 2 Te 3 O 9 , Y 2 Te 4 O 11 , Y 2 Te 5 O 13 and Y 2 Te 6 O 15 ), that contain only Te(IV), two tellurate phases, Y 6 TeO 12 and Y 2 TeO 6 , appear in an oxygen flow, under which the oxidation of Te(IV) to Te(VI) occurs. 18 In the Y 2 O 3 -TeO 2 system, the crystal structures of some defined members were refined from single crystals, as the structures of Y 2 TeO 6 (SG P2 1 2 1 2 1 ), 31 Y 2 Te 4 O 11 (SG P2/c) 33 The present paper reports a detailed analysis of the phases' formations in the Y 2 O 3 -TeO 2 system by solid state synthesis under oxygen flow, starting from the simple oxides. The never yet reported structure of the pure phase Y 6 TeO 12 is also presented here, studied by X-ray diffraction.…”

Pr3S2Cl2[AsS3]: A Praseodymium(III) Sulfide Chloride Thioarsenate(III) with Double Chains of Condensed [SPr4]10+ Tetrahedra

“…Whereas the latter show a tetrahedral structure, the arsenate(III) anions [AsCh 3 ] 3-are made up of only three chalcogen atoms and a stereochemically active, nonbinding electron-pair (lone pair) at the As 3+ cation resulting in the shape of a pyramidal ψ 1 -tetrahedron according to the Valence Shell Electron Pair Repulsion (VSEPR) concept. [1] The interest in lanthanoid-doped rare-earth metal oxosemimetalates, [2,3] in which the synergy between f-f or f-d transitions of the lanthanoid and s-p transitions of the metalloid lone-pair cations play a deciding role for their luminescence properties, [4] has tremendously increased recently. As a consequence, different compounds with ψ 1 -tetraedral oxoarsenate(III) anions [AsO 3 ] 3-, e.g.…”

Chloride Derivatives of Lanthanide Ortho‐Oxomolybdates: 1. Structural Comparison, Magnetic Properties, and Luminescence of the LnCl[MoO4] Representatives with the Smaller Lanthanides (Ln = Sm–Lu)

“…Lanthanide compounds containing complex oxoanions are the subject of numerous research topics, since those materials promise not only interesting crystal structures, but also some appealing properties. Compounds like La 3 F 3 [Si 3 O 9 ] [1] or Y 2 Te 4 O 11 [2], for example, have proven to be suitable host materials for luminescence applications. However, most of these materials represent non-metalates like silicates and phosphates, thus little is known about building…”

“…Sm 2 SCl 4 : d(Sm 3ϩ ϪCl Ϫ ) ϭ 276Ϫ321 pm[21]; Lu 2 CCl 2 : d(Lu 3ϩ ϪCl Ϫ ) ϭ 270 pm[22]). In the monoclinic structure the [LnCl 2 O 6 ] 11Ϫ polyhedra connect to layers parallel to the ab plane according to2…”