The study of incommensurate structures as a probe to reveal atomic interactions in crystals
-
Gervais Chapuis
Abstract
The structure of aperiodic crystals which in cludes incommensurate, quasi- and composite crystals is usu ally described in spaces of higher dimension, the so called su perspace. The main advantage of the superspace formalism is that an aperiodic structure in three dimensions recovers its full periodicity in higher dimensions. The symmetry prop erties of aperiodic crystals are obviously more convenient to describe in superspace too. The origin of the incommensurate nature of structures can often be found in competing inter atomic interactions. From molecular dynamics simulation of a simple three dimensional model with close-packed layers and a single degree of freedom for each particle, it is pos sible to find the existence conditions of commensurate and incommensurate phases. Incommensurate phases can already be predicted on the basis of nearest and next nearest neigh bour particle interactions only. We illustrate this principle of interactions with two examples of structures, Na2CO3 and K3In(PO4)2. These examples shows clearly the importance of non-oxygen interactions i.e. next nearest interactions for the formation of incommensurate structures.
© 2004 Oldenbourg Wissenschaftsverlag GmbH
Artikel in diesem Heft
- Self-reciprocal redundant vector stars
- Editorial: Incommensurate Crystallography of Modulated and Composite Crystals
- An elementary introduction to superspace crystallography
- Methods of structural analysis and computer program JANA2000
- Flexible phases, modulated structures and the transmission electron microscope
- X-ray diffuse scattering as precursor of incommensurate Peierls transitions in one-dimensional organic charge transfer conductors
- Incommensurate modulations made visible by the Maximum Entropy Method in superspace
- The study of incommensurate structures as a probe to reveal atomic interactions in crystals
- High temperature structures of LiKSO4 crystals: normal and incommensurate phases
- Incommensurate crystal structures in the elements at high pressure
- Structural phase transitions in iodine under high pressure
- Incommensurate crystal structure of LiCd4(VO4)3
- An electron and X-ray diffraction study of the compositely modulated barium nickel hollandite Bax(NixTi8—x)O16, 1.16 < x < 1.32, solid solution
- Book Reviews
- Books Received
Artikel in diesem Heft
- Self-reciprocal redundant vector stars
- Editorial: Incommensurate Crystallography of Modulated and Composite Crystals
- An elementary introduction to superspace crystallography
- Methods of structural analysis and computer program JANA2000
- Flexible phases, modulated structures and the transmission electron microscope
- X-ray diffuse scattering as precursor of incommensurate Peierls transitions in one-dimensional organic charge transfer conductors
- Incommensurate modulations made visible by the Maximum Entropy Method in superspace
- The study of incommensurate structures as a probe to reveal atomic interactions in crystals
- High temperature structures of LiKSO4 crystals: normal and incommensurate phases
- Incommensurate crystal structures in the elements at high pressure
- Structural phase transitions in iodine under high pressure
- Incommensurate crystal structure of LiCd4(VO4)3
- An electron and X-ray diffraction study of the compositely modulated barium nickel hollandite Bax(NixTi8—x)O16, 1.16 < x < 1.32, solid solution
- Book Reviews
- Books Received
