Three-dimensional distribution of polymorphs and magnesium in a calcified underwater attachment system by diffraction tomography

Abstract

Biological materials display complicated three-dimensional hierarchical structures. Determining these structures is essential in understanding the link between material design and properties. Herein, we show how diffraction tomography can be used to determine the relative placement of the calcium carbonate polymorphs calcite and aragonite in the highly mineralized holdfast system of the bivalve Anomia simplex. In addition to high fidelity and non-destructive mapping of polymorphs, we use detailed analysis of X-ray diffraction peak positions in reconstructed powder diffraction data to determine the local degree of Mg substitution in the calcite phase. These data show how diffraction tomography can provide detailed multi-length scale information on complex materials in general and of biomineralized tissues in particular.

Techniques to assess bone ultrastructure organization: orientation and arrangement of mineralized collagen fibrils

“…Briefly, reconstruction techniques used in X-ray absorption tomography have been applied to tomographically reconstruct information from specific q-ranges in the diffraction patterns. This can be used to distinguish different materials [154], tissues [155], tissue features or composition [156,157] within a sample. However, such approaches assume isotropic azimuthal scattering, ignoring the anisotropy in the diffraction patterns.…”

MultiRef: software platform for Rietveld refinement of multiple powder diffractograms fromin situ, scanning or diffraction tomography experiments

“…Diffraction tomography gives the possibility of non-invasively probing complex materials (Bleuet et al, 2008;Á lvarez-Murga et al, 2012;Leemreize et al, 2013Leemreize et al, , 2014Birkbak et al, 2015). In a recent study, MultiRef was used to perform Rietveld refinements on reconstructed data sets, thus allowing for in-depth analysis of tomographically reconstructed diffractograms (Frølich, Leemreize, Jakus et al, 2016).…”

“…2(a) shows a phase contrast tomographic image of the slice investigated by diffraction tomography and shows that the crystals are clustered into aggregates. The input data were reconstructed diffractograms (Leemreize et al, 2013) from diffraction tomography data collected at beamline 1-ID at the APS (Frølich, Leemreize, Jakus et al, 2016).…”

Calcite nucleation on the surface of PNIPAM–PAAc micelles studied by time resolved in situ PXRD

“…These materials make up the structural support of many organisms. [3][4][5][6][7][8][9][10] Many advancements have recently been made in the understanding of calcium carbonate nucleation pathways in general; these studies have highlighted prenucleation behaviour and amorphous precursor phases. 2 Calcite formation has been studied in both biogenic and a wide range of synthetic samples.…”