Assessment of structural order indices in kaolinites: A multi-technique study including EXAFS

This work presents a study of the structural properties on four representative kaolinite samples. Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Thermochemical Analyses (DTA/TGA), and Near Edge Structure (XANES) Extended Absorption Fine (EXAFS) spectroscopy measurements were carried out, different empirical indices that quantify order assessed. Also, XRD patterns EXAFS signals compared to those corresponding idealized defect-free structures calculated theoretically, analyze effects related disorder real The at scales (crystallographic, superficial, local) was comprehensively examined for samples, correlations between performed discussed, including Debye-Waller factor obtained from Si K-edge measurements. proposed methodology shows is suitable complementary technique can provide valuable information about local environments in natural kaolinites.