Contributions on the thermal behaviour of sulphates XVII. 1 Single crystal structure refinements of In2 (SO4)3 and Ga2 (SO4)3
| Autor: | R. Gruehn, M. Krause |
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| Rok vydání: | 1995 |
| Předmět: | |
| Zdroj: | Zeitschrift für Kristallographie - Crystalline Materials. 210:427-431 |
| ISSN: | 2196-7105 2194-4946 |
| DOI: | 10.1524/zkri.1995.210.6.427 |
| Popis: | Using chemical transport reactions well-shaped crystals of In2(SO4)3 and Ga2(SO4)3 can be prepared in a temperature gradient (T 2 → T 1) using Cl2 as transport agent. The two modifications of In2(SO4)3 were formed by variation of the transport temperature. The low-temperature modification of In2(SO4)3 (898 K → 848 K) is isostructural to monoclinic Fe2(SO4)3 and crystallizes in P21/n with a = 8.570(2) Å, b = 8.908(2) Å and c = 12.0521(1) Å, β = 91.05(3)°, Z = 4. The high-temperature modification of In2(SO4)3 (1023 K → 973 K) as well as Ga2(SO4)3 (923 K → 873 K) is isostructural to rhombohedral Fe2(SO4)3 and crystallizes in the rhombohedral space group R[unk] with a = 8.440(2) (8.054(2)) Å, c = 23.093(2) (21.840(2)) Å, Z = 6 (hexagonal setting). The crystal structures were refined to a residual R 1 = 0.028 using 1710 unique reflections with F o ≥ 4σ · (F o) for monoclinic In2(SO4)3 and to R 1 = 0.031(0.037) (571(587) unique reflections with F o ≥ 4σ(F o)) for rhombohedral In2(SO4)3(Ga2(SO4)3). The structures consist of MO6-octahedra and SO4-tetrahedra, which are linked via common corners to a three-dimensional network. |
| Databáze: | OpenAIRE |
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