Felix Hofmann

My tutorial teaching at Trinity covers the Mechanics and Materials parts of the Engineering Science course. Tutorials happen in groups of 2 or 3 students and are an excellent opportunity to discuss the material in detail and address challenging questions as they arise. In the Department of Engineering Science, I give lecture courses on solid mechanics and materials, supervise undergraduate and graduate student projects and organise some of the materials-oriented labs.

Atomic scale defects are central to the mechanical, physical and failure properties of almost all crystalline materials. These defects may, for example, be introduced by mechanical deformation, chemical changes or irradiation. I am interested in characterising the structure of atomic-scale defects and using this information to better understand the dramatic changes they can cause. To study defects, my group uses a wide range of experimental techniques, concentrating in particular on X-ray diffraction. We also develop new experimental techniques, such as laser-induced transient grating spectroscopy, to probe defect-induced changes in e.g. elastic and thermal transport properties. These experiments are combined with material models that cover a wide range of length scales, from considering single atoms to macroscopic components.

In my group we apply these techniques to challenging material systems for technologies that drive societal change. For example, a significant part of our effort is focussed on materials for future fusion reactors. We also work on developing new materials for extreme environments, as well as trying to gain a better understanding of defects in materials that appear in nature, e.g. biological materials and Earth materials.

My group’s research has benefitted from substantial funding from the European Research Council (Starting Grant 2016), The Leverhulme Trust (Research Project Grant 2016), as well as the Engineering and Physical Sciences Research Council (NEUP-EPSRG grant 2019).

Abdallah Reza, Hongbing Yu, Kenichiro Mizohata, Felix Hofmann, ‘Thermal diffusivity degradation and point defect density in self-ion implanted tungsten’, Acta Materialia (2020)

Felix Hofmann, Nicholas W. Phillips, Suchandrima Das, Phani Karamched, Gareth M. Hughes, James O. Douglas, Wonsuk Cha, Wenjun Liu, ‘Nanoscale imaging of the full strain tensor of specific dislocations extracted from a bulk sample’, Physical Review Materials 4, 1 (2020), 013801

S. Das, F. Hofmann, E. Tarleton, ‘Consistent determination of geometrically necessary dislocation density from simulations and experiments’, International Journal of Plasticity 109 (2018), 18-42

F. Hofmann, E. Tarleton, R.J. Harder, N.W. Phillips, P.W. Ma, J.N. Clark, I.K. Robinson, B. Abbey, W. Liu, C.E. Beck. ‘3D lattice distortions and defect structures in ion-implanted nano-crystals’, Scientific Reports 7 (2017) 45993

Felix Hofmann, Daniel R. Mason, Jeffrey K. Eliason, Alexei A. Maznev, Keith A. Nelson, Sergei L. Dudarev, ‘Non-contact measurement of thermal diffusivity in ion-implanted nuclear materials’, Scientific Reports 5 (2015), 16042

F. Hofmann, D. Nguyen-Manh, M.R. Gilbert, C.E. Beck, J.K. Eliason, A.A. Maznev, W. Liu, D.E.J. Armstrong, K.A. Nelson, S.L. Dudarev, ‘Lattice swelling and modulus change in a helium-implanted tungsten alloy: X-ray micro-diffraction, surface acoustic wave measurements, and multiscale modelling’, Acta Materialia 89 (2015), 352-363

F. Hofmann, B. Abbey, W. Liu, R. Xu, B.F. Usher, E. Balaur, Y. Liu, ‘X-ray micro-beam characterization of lattice rotations and distortions due to an individual dislocation’, Nature Communications 4 (203), 2774

You can see a full list of my publications here.