Ross Harder1 Mathew Cherukara1 Subramanian Sankaranarayanan1 Kiran Sasikumar1

1, Argonne National Laboratory, Argonne, Illinois, United States

Coherent x-ray diffractive imaging (CXDI) can now reach down to sub ten nanometer structural imaging of materials[1]. When done in the Bragg geometry one can also image distortions of the lattice with 10−5 sensitivity [2, 3]. Bragg CDI is also highly compatible with in-situ and operando studies of materials owing to the relatively large free space around the sample.
Recently we have conducted imaging experiments with both catalytic systems and ultrafast laser pump – x-ray probe of energy transport by phonons in nanomaterials[4]. To quantify the response seen in the materials there is an increased requirement for image analysis to understand the physical processes occurring.
Advanced image analysis and molecular dynamics (MD) simulations are now scaling in the opposite direction of CXDI. These computational methods are reaching UP to the length/time scales achieved in the imaging experiments. Image meshing techniques can be used to create models of the actual samples in an experiment, which can then feed into multi-million atom MD and finite element simulations over hundreds of picoseconds[5].
Building a complete workflow to understand nanoscale phenomena with atomistic origins is the goal the MAUI (Modeling, Analysis and Ultrafast Imaging) project at Argonne National Laboratory. Specialists in coherent imaging, ultrafast laser science, 4D image analysis, math and computer science have teamed up with molecular dynamics simulations experts to develop these tools.
This talk will focus on recent efforts and results coming out of the MAUI team.

[1] Y. Takahashi et al., English, Physical Review B 80, 054103 (Aug. 2009).
[2] M. A. Pfeifer et al., Nature 442, 63–66 (July 2006).
[3] I. Robinson et al., Nat Mater 8, 291–298 (Apr. 2009).
[4] A. Ulvestad et al., J. Phys. Chem. Lett. 7 (15), 3008–3013 (Jul. 2016).
[5] Y. Li et al., Scientific reports 5 (2015).