ISSN:
1600-5724
Quelle:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Thema:
Chemie und Pharmazie
,
Geologie und Paläontologie
,
Physik
Notizen:
Molecular dynamics has been used to estimate the properties of a two-dimensional crystal exhibiting a second-order soft-mode phase transition. Using a vibrational potential for the crystal which is temperature independent, the essential features observed experimentally in the coherent scattering from analogous real systems are reproduced in the computer simulation. The potential consists of an effective one-particle component with multiple minima and a harmonic nearest-neighbour coupling component. It is emphasized that the coupling component is essential to reproduce correctly the qualitative features not only of the diffuse scattering, but also of the mean-square displacements as a function of temperature. The condition for appearance of a cusp at TC in the mean-square displacement versus temperature curve is discussed and the formation of superlattice peaks in the diffuse scattering is demonstrated.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1107/S0108767387098726
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