636 – Modulation of physico-chemical processes by elastic strain engineering
24 rue de l’Epitaphe
25000 Besançon, France
C/ Eric Kandel, 2
28906, Getafe, Madrid, Spain
Large elastic deformations modify the electronic structure of materials, leading to changes of their physical and chemical properties, which can even be tuned as a function of the applied strain tensor. The concept of elastic strain engineering is not new and has been successfully applied to enhance the electron and hole mobility in complementary metal-oxide semiconductors, to transform paramagnetic into ferromagnetic ones, or to increase the catalytic activity of metals. In general, the effect of elastic deformations on the physical and chemical properties of materials becomes relevant when elastic strain levels ≥ 1-2% are reached. These strains levels can only be achieved, however, under conditions of hydrostatic pressure in bulk solids because tensile or shear elastic deformations are relaxed for values < 1% due to the nucleation of defects (dislocations, fracture). Nevertheless, large elastic deformations in traction or shear (which can reach values close to the theoretical limit of 10%) can be achieved nowadays in different types of nanomaterials (nanowires, two-dimensional materials), thin films or bulk materials with an architectured microstructure. This holds true whatever the materials class, and metals, ceramic or organic materials may be considered.
The possibility to apply large elastic strains provides a way to tailor the physico-chemical properties of materials (electronic, optical, magnetic, catalytic, etc.) by systematically varying the 6 components of the elastic strain tensor, opening a huge field to develop new functional materials with optimal properties for specific applications. The topic is interdisciplinary because it lies at the intersection among mechanics, physics, chemistry, materials science and surface science. It moreover involves fundamental theoretical analyses of the mechano-chemical coupling as well as state-of-the-art processing and in-situ characterization techniques to manufacture highly strained materials and measure their multi-physical properties.