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Order causes secondary Bragg peaks in soft materials
Stephan Förster1, Andreas Timmann, Carsten Schellbach
1Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, D-20146 Hamburg, Germany. forster@chemie.uni-hamburg.de
Nature Materials
|August 28, 2007
Summary
Bragg peaks in soft materials arise from lattice coherence, not structural changes. This finding simplifies analysis of ordered soft materials, enabling new applications in nanotechnology.
Area of Science:
- Soft Matter Physics
- Materials Science
- Crystallography
Background:
- Highly ordered soft materials often show Bragg peaks that are difficult to index with standard crystallographic models.
- Previous interpretations suggested these peaks resulted from structural changes during ordering, limiting their use in applications requiring homogeneous structures.
Purpose of the Study:
- To demonstrate that Bragg peaks in homogeneous ordered soft materials are an intrinsic property related to lattice coherence.
- To provide a unified framework for analyzing diffraction patterns across diverse soft materials.
Main Methods:
- Analysis of Bragg peak characteristics in homogeneous ordered soft materials.
- Theoretical consideration of finite coherence within crystalline lattices.
Main Results:
- Bragg peaks are an inherent property of homogeneous ordered soft materials due to finite lattice coherence.
- This understanding allows quantitative analysis of diffraction patterns for various soft materials.
- Enables a unified description of order, orientation, and epitaxial relationships.
Conclusions:
- The observed Bragg peaks are not indicative of structural inhomogeneity but rather a consequence of lattice coherence.
- This provides a more accurate and unified approach to studying ordered soft materials.
- Facilitates the design and application of nano- and microstructured soft materials.
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