Differences between bond lengths in biogenic and geological calcite

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • E. Zolotoyabko - , Technion-Israel Institute of Technology (Author)
  • E. N. Caspi - , Nuclear Research Center-Negev (Author)
  • J. S. Fieramosca - , Argonne National Laboratory (Author)
  • R. B. Von Dreele - , Argonne National Laboratory (Author)
  • F. Marin - , Université de Bourgogne (Author)
  • G. Mor - , Weizmann Institute of Science (Author)
  • L. Addadi - , Weizmann Institute of Science (Author)
  • S. Weiner - , Weizmann Institute of Science (Author)
  • Y. Politi - , Weizmann Institute of Science (Author)

Abstract

We used high-resolution neutron powder diffraction to accurately measure the atomic positions and bond lengths in biogenic and geological calcite. A special procedure for data analysis was developed in order to take into account the considerable amounts of magnesium present in all the investigated samples. As a result, in biogenic calcite we found some atomic bonds to have significantly different lengths as compared to those in geological calcite, after the contribution of magnesium is accounted for. The maximum effect (elongation up to 0.7%) was found for the C-O bonds. We also analyzed changes in frequencies and spectral widths of normal vibrations of carbonate groups in biogenic calcite (as compared to geological calcite) measured by Raman and Fourier transform IR techniques. Surprisingly, the frequency shifts after subtracting the magnesium contribution are close to zero. At the same time, substantial spectral broadening (up to 1.2%) in biogenic calcite as compared to geological samples was detected. Possible explanations for the experimental findings are discussed.

Details

Original languageEnglish
Pages (from-to)1207-1214
Number of pages8
JournalCrystal Growth and Design
Volume10
Issue number3
Publication statusPublished - 3 Mar 2010
Peer-reviewedYes
Externally publishedYes

External IDs

ORCID /0000-0002-2872-8277/work/142239177