The high-temperature superionic behaviour of Ag(2)S
Powder neutron diffraction and molecular dynamics (MD) simulations have been used to investigate the structural behaviour of silver sulfide, Ag2S, at elevated temperatures. Above ∼450 K Ag2S adopts the β phase in which the S2- posses a body-centred cubic arrangement. Analysis of the neutron diffract...
| المؤلفون الرئيسيون: | , , , , |
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| التنسيق: | Journal article |
| اللغة: | English |
| منشور في: |
2002
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| الملخص: | Powder neutron diffraction and molecular dynamics (MD) simulations have been used to investigate the structural behaviour of silver sulfide, Ag2S, at elevated temperatures. Above ∼450 K Ag2S adopts the β phase in which the S2- posses a body-centred cubic arrangement. Analysis of the neutron diffraction is in good agreement with the previously proposed structural model in which the Ag+ predominantly reside within the tetrahedral interstices. At ∼865 K Ag2S transforms to the α phase in which the anion sublattice adopts a face-centred cubic arrangement. Structural refinements of this phase indicate that the cations are distributed predominantly in the tetrahedral cavities but with a significant fraction in the octahedral holes. MD simulations, using established potentials for this compound, confirm the stability of the two high-temperature superionic phases and show good agreement with the measured Ag+ distribution within the unit cell. |
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