Analyse Quantitative de Texture: un outil d'interprétation des propriétés anisotropes entre poudre et monocristal; ou, "Quantitative Texture Analysis: a Pot Pourri"

The anisotropy of macroscopic physical properties of polycristalline samples can be observed only if the individual crystallites of the sample are preferentially oriented. Interest in Quantitative Texture Analysis (QTA) played a crucial rule in the past, and still continue nowadays, for instance to optimise mechanical properties of metallic alloys, to understand the deformation processes in geophysic phenomena or to limit materials wastes during industrial processes. Recently, the elaboration of materials having anisotropic physical properties started up again interest in QTA. For instance in ferro and piezo-electrics, superconductors, ionic conductors, composites, polymers ... The use of diffraction (x-rays, neutrons and electrons) today have replaced the older techniques for QTA characterisation like polarised light microscopy, only qualitative and often incomplete: - for simulation of some macroscopic physical properties, consequences of anisotropic tensors (mechanical properties, anisotropic acoustic wave propagation, magnetic properties), which can be modelised using QTA data. - to understand correlation between microscopic (intrinsic) tensors and their macroscopic revelation in textured polycrystalline samples (piezo and ferroelectricity ...) - to determine the growth modes (epitaxy, oriented growths ...), then to optimise elaboration processes. The limit of some characterisation techniques has also benefited of the QTA formalism. For instance: - in polarised EXAFS, thanks to the combined use of P-EXAFS and QTA, to allow the determination of some structural parameters non accessible without polarised x-rays and textured samples - by coupling the Rietveld and WIMV approaches in the o-called combined analysis structure-texture-stress - and in QTA itself, by using the full profile methodologies for the study of partially crystallised samples (turbostratic, polymers ...) All these approaches are described here.