| Autor: |
Baldauf, Jasper Arne, Kösters, Jutta, Janka, Oliver, Pöttgen, Rainer |
| Předmět: |
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| Zdroj: |
Zeitschrift für Kristallographie. Crystalline Materials; Nov2024, Vol. 239 Issue 11/12, p345-351, 7p |
| Abstrakt: |
Well-shaped single crystals of Ta11Pt4 formed through crucible attack during phase analytical studies in the Ca–Pt–Zn system. Phase-pure Ta11Pt4 was subsequently obtained from the pure elements by arc-melting. The crystal structure of Ta11Pt4 was refined from single crystal X-ray diffractometer data: P42/mnm, a = 992.94(8), c = 516.59(4) pm, wR2 = 0.0672, 576 F2 values and 27 variables. Ta11Pt4 is a new coloring variant in the large family of sigma phase compounds. Of the five crystallographically independent sites, four are occupied by tantalum and the fifth one by platinum in a fully ordered manner. The platinum atoms have distorted icosahedral coordination by 11 tantalum and 1 platinum atom. Two of these Ta@Ta11Pt icosahedra are condensed by interpenetration forming a Pt2 pair with 275 pm Pt–Pt distance. These double-icosahedra are the monomeric building unit of the Ta11Pt4 structure and further condense via common edges to a three-dimensional dense sphere packing. The Ta–Ta distances cover a broader range from 256 to 329 pm, comparable to the structure of bcc tantalum. Temperature dependent magnetic susceptibility studies indicate Pauli paramagnetism. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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