2024-03-29T08:54:42Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/121612010-06-27T22:00:00Zcom_10261_34com_10261_5col_10261_287
Reversible phase transitions in Na₂S under pressure: a comparison with the cation array in Na₂SO4
Vegas, Ángel
Grzechnik, A.
Syassen, K.
Loa, I.
Hanfland, M.
Jansen, M.
Phase transition
Cation array
Pressure
The structural behavior of the antifluorite Na2S, disodium sulfide, has been studied under pressure up to 22 GPa by in situ synchrotron X-ray diffraction experiments in a diamond anvil cell at room temperature. At approximately 7 GPa, Na2S undergoes a first phase transition to the orthorhombic anticotunnite (PbCl2) structure (Pnma, Z = 4). The lattice parameters at 8.2 GPa are a = 6.707 (5), b = 4.120 (3), c = 8.025 (4) Å. At approximately 16 GPa, Na2S undergoes a second transition adopting the structure of the Ni2In-type (P63/mmc, Z = 2). The lattice parameters at 16.6 GPa are a = 4.376 (18), c = 5.856 (9) Å. Both pressure-induced phases have been confirmed by full Rietveld refinements. An inspection of the cation array of Na2SO4 reveals that its Na2S subarray is also of the Ni2In-type. This feature represents a new example of how the cation arrangements in ternary oxides correspond to the topology of the respective binary compounds. We discuss analogies between the insertion of oxygen and the application of pressure.
Peer reviewed
2009-04-07T10:56:48Z
2009-04-07T10:56:48Z
2001-04
artículo
http://purl.org/coar/resource_type/c_6501
Acta Crystallographica B57: 151-156 (2001)
0108-7681
http://hdl.handle.net/10261/12161
10.1107/S0108768100016621
en
http://dx.doi.org/10.1107/S0108768100016621
open
6080 bytes
image/gif
International Union of Crystallography