Microscopy and Microanalysis

Biological Applications

Optimizing Electron Backscatter Diffraction of Carbonate Biominerals—Resin Type and Carbon Coating

Alberto Pérez-Huertaa1 c1 and Maggie Cusacka1

a1 Department of Geographical and Earth Sciences, University of Glasgow, G12 8QQ Glasgow, UK

Abstract

Electron backscatter diffraction (EBSD) is becoming a widely used technique to determine crystallographic orientation in biogenic carbonates. Despite this use, there is little information available on preparation for the analysis of biogenic carbonates. EBSD data are compared for biogenic aragonite and calcite in the common blue mussel, Mytilus edulis, using different types of resin and thicknesses of carbon coating. Results indicate that carbonate biomineral samples provide better EBSD results if they are embedded in resin, particularly epoxy resin. A uniform layer of carbon of 2.5 nm thickness provides sufficient conductivity for EBSD analyses of such insulators to avoid charging without masking the diffracted signal. Diffraction intensity decreases with carbon coating thickness of 5 nm or more. This study demonstrates the importance of optimizing sample preparation for EBSD analyses of insulators such as carbonate biominerals.

(Received December 05 2008)

(Accepted March 12 2009)

Correspondence:

c1 Corresponding author. E-mail: Alberto.PerezHuerta@ges.gla.ac.uk