Crystal Structure Refinements of Isomertieite, Pd11Sb2As2, and Törnroosite, Pd11As2Te2
| Autor: | Andrey A. Zolotarev, Tatiana L. Grokhovskaya, O. V. Karimova, Vladislav V. Gurzhiy |
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| Rok vydání: | 2016 |
| Předmět: | |
| Zdroj: | The Canadian Mineralogist. 54:511-517 |
| ISSN: | 1499-1276 0008-4476 |
| Popis: | The crystal structures of isomertieite, Pd 11 Sb 2 As 2 , (I) from the Monche-Tundra intrusion, Monchegorsk Igneous Complex (MIC), Kola Peninsula, Russia, and tornroosite, Pd 11 As 2 (Te 1.7 Bi 0.3 ) Σ2 (IIa) and Pd 11 As 2 (Te 1.3 Bi 0.7 ) Σ2 (IIb) from the South Sopcha intrusion, MIC, Kola Peninsula, Russia, were refined on the basis of X-ray diffraction data collected from single crystals. The two minerals were found to exhibit the same structure, cubic, space group Fd m , Z = 8, with unit-cell parameters for (I): a 12.297(5) A, V 1859.3(2) A 3 ; for (IIa): a 12.350(2) A, V 1883.6(4) A 3 ; and for (IIb): a 12.370(1) A, V 1892.9(3) A 3 . The structures were refined to R 1 = 0.056 (I), 0.014 (IIa), 0.018 (IIb). The isomertieite crystal-chemical formula was confirmed. The Bi-for-Te substitution in tornroosite was found to not affect the main structural topology. In the structure of the two minerals there are three symmetrically independent Pd positions: M 1, M 2, and M 3. M 1 forms M 1As 4 tetrahedra, M 2 forms M 2As 2 Sb 2 (I) or M 2As 2 Te 2 (II) tetrahedra, and M 3 forms M 3Sb 3 (I) or M 3Te 3 (II) triangles connected together via common edges and forming a framework in the structure. |
| Databáze: | OpenAIRE |
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