Atomic Structure of Biogenic Aragonite
B. Pokroy
J. S. Fieramosca
R. B. Von Dreele
A. N. Fitch
E. N. Caspi
E. Zolotoyabko
10.1021/cm070187u.s004
https://acs.figshare.com/articles/dataset/Atomic_Structure_of_Biogenic_Aragonite/3000040
Atomic positions in geological aragonite and biogenic aragonite, obtained from several mollusk shells,
were precisely measured by high-resolution neutron diffraction, which is more sensitive than X-ray
diffraction to the positions of light atoms, C and O, in the CaCO<sub>3</sub> structure. Comparable analysis of
atomic positions revealed, for the first time, the changes in some bond lengths and atomic configurations
in biogenic specimens with respect to geological ones. Most pronounced are modifications in the aplanarity
of the carbonate groups. These modifications correlate with the observed shifts of the ν<sub>2</sub> frequency in the
IR absorption spectra. The changes in atomic positions as well as the changes in lattice parameters detected
by high-resolution X-ray diffraction are attributed to the interaction between organic macromolecules
and growing crystallites during biomineralization. The obtained results allow us deeper understanding of
the specific routes used by nature for growing bio-composites with superior characteristics.
2007-06-26 00:00:00
bond lengths
CaCO 3 structure
biogenic aragonite
neutron diffraction
carbonate groups
Biogenic AragoniteAtomic positions
modification
light atoms
ν2 frequency
lattice parameters
Comparable analysis
mollusk shells
biogenic specimens
Atomic Structure
IR absorption spectra