title: Application of total X-ray scattering methods and pair distribution function analysis for study of structure of biominerals.
abstract: Total X-ray scattering and pair distribution function (PDF) analysis, using a high-energy synchrotron source, allow direct study of the short- and intermediate-range structure that distinguish amorphous, structurally disordered, and nanocrystalline biominerals. For such samples in which diffuse scatter is a significant component, care must be taken in the experimental procedures to optimize data quality and extract the useful signal necessary to calculate the PDF. General methods are described for data collection and processing, including commonly used software programs. Methods for analysis and interpretation of PDFs are presented, including direct real-space refinement and reverse Monte Carlo methods. Greater application of PDFs to amorphous and poorly crystallized biominerals will provide new insight into structure, especially over length scales that are not probed by other techniques. The rapid data collection available at synchrotron facilities also allows in situ kinetic studies of reactions involving biominerals.
authors.affiliation: Department of Geosciences, Stony Brook University, Stony Brook, New York, USA. Electronic address: rjreeder@stonybrook.edu.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Reeder
authors.forename: F Marc
authors.initials: FM
authors.lastname: Michel
mesh_terms: D002119:Calcium Carbonate / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D005293:Ferritins / Q000737:chemistry*; D007700:Kinetics; D009010:Monte Carlo Method; D053758:Nanoparticles / Q000737:chemistry; D033362:Powder Diffraction; D017356:Synchrotrons; D014961:X-Ray Diffraction
chemical_list: D005290:Ferric Compounds; C092844:ferric oxyhydroxide; D005293:Ferritins; D002119:Calcium Carbonate
keywords: Amorphous calcium carbonate; Ferrihydrite; Ferritin; Pair distribution function; Short-range order; Synchrotron radiation; Total scattering; X-ray diffraction