Principal investigator : Tilman Grünewald
Biological materials exhibit outstanding mechanical properties and combine seemingly contradictory properties like strength and toughness together with intricate structural responses during growth and healing [1]. This is achieved by the intricate, hierarchical organization of biomaterials on the nanostructural and crystal structural level [2], the so-called crystallographic texture. The determination of the crystallographic texture and the local (...)

Principal investigator : Patrick Ferrand
In the optical regime, ptychography is becoming a new competitive microscopy method mostly thanks to its capability to image quantitatively the phase shift introduced by the sample.
We have established a vectorial formalism that allows to use ptychography even on anisotropic (e.g., birefringent, but not only) specimens. We have demonstrated the capability of of vectorial ptychography to map the four parameters of the Jones matrix of an (...)

Biocrystallization involves extraordinary complex and regular biochemical processes where living organisms control the crystalline form and texture of their organo-mineral components. Although these crystals present a wide variety of shapes, associated to various organic materials, the observation of a nanoscale granular structure common to almost all calcareous crystallizing organisms, associated to an extended crystalline coherence, underlies a generic biomineralization and assembly (...)

Principal investigator : Virginie Chamard
Imaging crystalline properties at the nano-scale
In the x-ray range, focusing components have very limited performances. Therefore, solving the inverse problem is a relevant strategy, which allows (i) to reach high spatial resolution in spite of limited apertures, (ii) to obtain quantitative information of the object (related to physical properties such as density, strain, crystal coherence, etc.).
Our efforts focus on Bragg ptychography, a (...)