| Autor: |
Ihli J; School of Chemistry , University of Leeds , Leeds LS2 9JT , UK . Email: Johannes.Ihli@materials.ox.ac.uk ; Email: F.Meldrum@leeds.ac.uk., Clark JN; Stanford PULSE Institute , SLAC National Accelerator , Menlo Park , California 94025 , USA., Kanwal N; School of Chemistry and EaStCHEM , University of St. Andrews , North Haugh , St. Andrews , KY16 9ST , UK., Kim YY; School of Chemistry , University of Leeds , Leeds LS2 9JT , UK . Email: Johannes.Ihli@materials.ox.ac.uk ; Email: F.Meldrum@leeds.ac.uk., Holden MA; School of Chemistry , University of Leeds , Leeds LS2 9JT , UK . Email: Johannes.Ihli@materials.ox.ac.uk ; Email: F.Meldrum@leeds.ac.uk., Harder RJ; Advanced Photon Source , Argonne , Illinois 60439 , USA., Tang CC; Diamond Light Source , Harwell Science and Innovation Campus , Didcot , Oxfordshire OX11 0DE , UK., Ashbrook SE; School of Chemistry and EaStCHEM , University of St. Andrews , North Haugh , St. Andrews , KY16 9ST , UK., Robinson IK; London Centre for Nanotechnology , University College London , London WC1H 0AH , UK.; Condensed Matter Physics and Materials Science , Brookhaven National Lab. Upton , NY 11973-5000 , USA., Meldrum FC; School of Chemistry , University of Leeds , Leeds LS2 9JT , UK . Email: Johannes.Ihli@materials.ox.ac.uk ; Email: F.Meldrum@leeds.ac.uk. |
| Abstrakt: |
Soluble additives provide a versatile strategy for controlling crystallization processes, enabling selection of properties including crystal sizes, morphologies, and structures. The additive species can also be incorporated within the crystal lattice, leading for example to enhanced mechanical properties. However, while many techniques are available for analyzing particle shape and structure, it remains challenging to characterize the structural inhomogeneities and defects introduced into individual crystals by these additives, where these govern many important material properties. Here, we exploit Bragg coherent diffraction imaging to visualize the effects of soluble additives on the internal structures of individual crystals on the nanoscale. Investigation of bio-inspired calcite crystals grown in the presence of lysine or magnesium ions reveals that while a single dislocation is observed in calcite crystals grown in the presence of lysine, magnesium ions generate complex strain patterns. Indeed, in addition to the expected homogeneous solid solution of Mg ions in the calcite lattice, we observe two zones comprising alternating lattice contractions and relaxation, where comparable alternating layers of high magnesium calcite have been observed in many magnesium calcite biominerals. Such insight into the structures of nanocomposite crystals will ultimately enable us to understand and control their properties. |
