The project entitled “Characterization of defects by Advanced Diffraction techniques to evaluate micro-crystals deformation stages” (CharADiff) aims at gaining a detailed understanding of the mechanics of small scale objects (micro and nano-crystals) by the implementation of an unprecedented combination of recent and specifically-developed in-situ cutting-edge x-ray diffraction techniques: 1) in-situ coherent x-ray diffraction that enables to detect and evaluate the number of lattice defects (dislocations) in small scale crystals during mechanical solicitation; 2) in-situ micro-Laue diffraction that allows for studying the nature and sequence of activated dislocation slip systems during plastic deformation of small objects; 3) post-mortem Bragg ptychography that provides a 3D image of the displacement field caused by lattice defects left in the deformed objects and 4) ptychographic topography, a novel technique developed in this project, to map individual lattice defects while remaining compatible with future in-situ deformation studies. These techniques are applied to a unique system: InSb semi-conductor micro-crystals of initial excellent crystalline quality whose mechanical properties have been already thoroughly studied, therefore being a robust benchmark.
The outcomes of this original methodology are two-fold:
- developing a tool box combining in-situ and post-mortem advanced diffraction techniques to characterize the deformation response of small scale objects (deformation stages and lattice defects storage): this will enrich the current knowledge on small scale mechanics, providing responses to some of the open questions still remaining in Materials Science on the effects of size reduction;
- assessing the complementarity between some of the most recent diffraction techniques developed at synchrotrons with the perspective to push their applicability to the forefront of their current use. Moreover, a new non-destructive imaging technique will be developed, ptychographic topography, with the strong perspective to be implemented within an in-situ setup, as another step forward.
The impact of the project is potentially far beyond the frontiers described above, in particular in the field of nanotechnology, where the x-ray diffraction techniques developed here could constitute non-destructive solutions to assess the crystalline quality of small-scale crystals that are the building blocks of miniaturized devices, therefore allowing for quantitative diagnostics and defect engineering.
To guarantee the success of this 36 month-project, a well thought consortium of French and Swiss experts has been settled, with strong complementarity in the fields of experimental and simulation approaches, as well as Materials Science and diffraction. A total of 86.4 person-months will be deployed by the consortium, including 9 permanent staffs and 2 post-doctoral fellows.
Monsieur Ludovic THILLY (Institut Pprime - Université de Poitiers)
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
PSI-SLS Paul Scherrer Institut - Swiss Light Source
PSI-PEM Paul Scherrer Institut - Photons for Engineering and Manufacturing
LPS Laboratoire de Physique des Solides CNRS
Pprime - UP Institut Pprime - Université de Poitiers
Help of the ANR 187,239 euros
Beginning and duration of the scientific project: January 2017 - 36 Months