| 1 | Author
| Wolfgang Jeitschko, HorstA. Mons, Ute Ch, Rodewald | Requires cookie* | | Title
| Preparation and Crystal Structure of the Calcium Rhenate(VI, VII) Ca5Re30 15.x  | | | Abstract
| The title compound was prepared by reaction of elemental calcium with the calcium metaper-rhenate Ca(ReC>4)2. Its crystal structure was determined from single-crystal X-ray data: Amm2, a = 560.31 (5)pm, b = 1572.4(1)pm, c = 719.91 (6)pm ,Z = 2 ,R = 0.033 for 930 structure factors and 46 variable parameters. The calcium atoms occupy three atomic sites, all with seven oxygen neighbors. Of the two different rhenium atoms one has square-pyramidal oxygen coordination with an average oxidation number +6.25. The other rhenium site (oxidation number +7) was refined as a split position with trigonal-bipyramidal (75%) and tetrahedral oxygen coordination (25%). One oxygen site remains unoccupied, whenever the tetrahedral rhenium site is occupied, resulting in the composition Ca5Re3 0 i4.75. A test for superconductivity of this black compound down to 1.5 K was negative. | | |
Reference
| Z. Naturforsch. 54b, 1483—1488 (1999); received August 16 1999 | | |
Published
| 1999 | | |
Keywords
| Crystal Structure, Mixed Valence, Rhenates, Perrhenates | | |
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| default:Reihe_B/54/ZNB-1999-54b-1483.pdf | | | Identifier
| ZNB-1999-54b-1483 | | | Volume
| 54 | |
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