Séminaire Upgrade : In-situ opportunities for Bragg Coherent Diffraction Imaging of Materials

Upgrade Table Ronde Energie et Développement Durable

 
Ian Robinson

(Condensed Matter Physics and Materials Science, Brookhaven National Lab, London Centre for Nanotechnology, UCL, London, UK)
 

The Bragg Coherent Diffraction Imaging (BCDI) method will be discussed for its abilities for in-situ imaging of energy materials.  BCDI’s greatest strength is to reveal 3D phase-contrast images of the interiors of crystals with image resolution in the 30nm range.  It achieves this through the projection of lattice displacements onto the diffraction Q-vector, showing up as a phase shift on a very sensitive scale: one lattice constant results in a phase shift of 2π.  Using this new channel of information about the detailed structures of crystals, we have found striking patterns of phase nano-domains within otherwise solid-looking crystals of micron dimension.  Since almost all materials are made up of microcrystals, this method has wide application in materials science and engineering and lies at the heart of a case for a new beamline at NSLS-II.

The presentation will discuss various materials studied by BCDI: domains introduced in Au by interdiffusion of Cu, faulted misfit domains on the surface of Au induced by Fe diffusion, insect virus crystals, SAPO-34 zeolite catalyst crystals and the Perovskite La0.5Ca0.5MnO3 (LCMO). Some of these images are shown below.

Formalités d’entrée :

accès libre dans l’amphi du pavillon d’Accueil.
Si la manifestation a lieu dans le Grand Amphi SOLEIL du Bâtiment Central merci de vous munir d’une pièce d’identité (à échanger à l’accueil contre un badge d’accès)

Contact : Sandrine Vasseur