 | Acta Crystallographica Section B Acta Crystallographica Section B STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS |
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![[Figure 3]](wu5006fig3mag.jpg)
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Figure 3
Lattice dynamics of KCl/KBr and its relationship to the thermal diffuse scattering contribution. (a) Harmonic phonon dispersion relation for KCl, calculated from the empirical potential of Catlow et al. (1977)  using the GULP code (Gale & Rohl, 2003; Gale, 2005). Thermal diffuse scattering is dominated by the lowest-energy phonons, which correspond to the transverse acoustic (TA) branch along the Δ (Γ–X) line in reciprocal space. The dispersion relation for KBr is essentially identical, except that the phonon frequencies are lower as a consequence of the larger mass of Br relative to Cl. (b) Comparison of experimental diffuse scattering patterns for KCl and KBr with the thermal diffuse scattering calculated using conventional harmonic lattice dynamics (LD) and supercell lattice dynamics (SCLD). The close correspondence amongst the three functions indicates that (i) as expected, the diffuse scattering is purely dynamical in origin for these compositional end-members, and (ii) that our implementation of the SCLD thermal diffuse scattering calculations gives sensible results. |
![[Figure 3]](wu5006fig3.jpg)
| STRUCTURAL SCIENCE CRYSTAL ENGINEERING MATERIALS |
ISSN: 2052-5206
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