Three dimensional materials science
Trained as an experimental physicist, my PhD was in the field of superconductivity. As a post doc at HASYLAB I was daily responsible for developing the first “hard x-ray” synchrotron instrument in the world. Jointly with Dr. D.J. Jensen from Risø Nat. Lab. I formulated a vision of using the hard x-rays to visualise the evolution of materials microstructures. In 2001 this work lead to the establishment of a Danish Center of Excellence: “Metal structures in 4D”, with the dual aim of developing 4D resolved instrumentation and exploiting it for basic studies in metal science. The center published more than 500 articles during its existence. The group was responsible for developing the first dedicated 3DXRD microscope at beamline ID11 at ESRF.
In 2012 I was granted an ERC Advanced grant. With this I started a new group at DTU, which has developed a diffraction based x-ray microscope in collaboration with beamline ID06 at ESRF. This involved R&D work on optics, detectors and algorithms. The microscope currently generates 3D movies of embedded grains, domains and defects in mm thick specimens at a spatial resolution of 100 nm. In 2017-18 we demonstrated two new advances that improved the resolution to 13 nm. First applications are within metallurgy, ferroics and energy materials. Motivated by the vision of multiscale materials science as a driver for “materials design by computing” one of four ‘flagship’ beamlines to be built in connection with the ESRF upgrade will be a second generation version of the hard x-ray diffraction microscope. The 3D grain mapping methodology has been transferred to electron microscopy and is used with laboratory x-rays. The latter use is commercialised by the spin out Xnovo Technologies.
In terms of materials science my prime interest is metal physics with a view to the fundamental understanding of processes such as nucleation and growth and plasticity. Recently I have worked on grain growth, combining 3D experiments and 3D modelling, in casu phase field modelling.
Related projects
Within an EU Adventure project “TotalCrystallography” an alternative route to crystallography was developed based on characterising individual grains in polycrystals. This expands the relevance of grain mapping studies to fields such as high pressure physics, geoscience and solar cell research. - Strain scanning procedures for studies of amorphous alloys, liquids and polymers, again extending the concept of 3D materials science.