Evolution of the microstructure and crystallographic orientation during shell growth in Psilunio littoralis and Nautilus belauensis

摘要: Thin sections of shells from different species mollusc have been analysed by X-ray synchrotron diffraction using the BM16 at European Synchrotron Radiation Facility (ESRF), Grenoble, France. A sequence 2-D patterns were acquired in transmission mode regular intervals across shell thickness. From 2D patterns, 2𝛉- and χ-scans calculated analysed. We studied evolution microstructures analysing several parameters scans: (1) intensity most intense aragonite reflections 2𝛉 scans; (2) crystallinity full width half maximum values main those (3) degree orientation crystals, measured angular (in angle) arches displayed Debye-Scherrer rings which appeared patterns. The determined sharp changes transitions between microstructurally distinct layers indicating that microstructural switch occurred very rapidly was precisely controlled.