Assessment of crystallographic influence on material properties of calcite brachiopods

Perez-Huerta, A., Cusack, M. and Zhu, W. (2008) Assessment of crystallographic influence on material properties of calcite brachiopods. Mineralogical Magazine, 72(2), pp. 563-568. (doi: 10.1180/minmag.2008.072.2.563)

Abstract

Calcium carbonate biominerals are frequently analysed in materials science due to their abundance, diversity and unique material properties. Aragonite nacre is intensively studied, but less information is available about the material properties of biogenic calcite, despite its occurrence in a wide range of structures in different organisms. In particular, there is insufficient knowledge about how preferential crystallographic orientations influence these material properties. Here, we study the influence of crystallography on material properties in calcite semi-nacre and fibres of brachiopod shells using nano-indentation and electron backscatter diffraction (EBSD). The nano-indentation results show that calcite semi-nacre is a harder and stiffer (H {approx} 3–5 GPa; E = 50–85 GPa) biomineral structure than calcite fibres (H = 0.4–3 GPa; E = 30–60 GPa). The integration of EBSD to these studies has revealed a relationship between the crystallography and material properties at high spatial resolution for calcite semi-nacre. The presence of crystals with the c-axis perpendicular to the plane-of-view in longitudinal section increases hardness and stiffness. The present study determines how nano-indentation and EBSD can be combined to provide a detailed understanding of biomineral structures and their analysis for application in materials science.

• Item Type: Articles
• Keywords: Biomineral, nano-indentation, electron backscatter diffraction (EBSD), c axis, calcite, brachiopods
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Cusack, Professor Maggie and Perez-Huerta, Dr Alberto
• Authors: Perez-Huerta, A., Cusack, M., and Zhu, W.
• Subjects: Q Science > QH Natural history
• College/School: College of Science and Engineering > School of Geographical and Earth Sciences
• Journal Name: Mineralogical Magazine
• Publisher: Mineralogical Society
• ISSN: 0026-461X
• ISSN (Online): 1471-8022
• Copyright Holders: Copyright © 2008 Mineralogical Society
• First Published: First published in Mineralogical Magazine 72(2):563-568
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher.

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
42931	1	Crystallography for biology - as easy as EBSD	Maggie Cusack	Biotechnology and Biological Sciences Research Council (BBSRC)	BB/E003265/1	School of Geographical and Earth Sciences