Epitaxial thin film growth for in-situ mechanical tensile experiments using advanced transmission electron microscopy

The project in the scope of research activities of the Advanced Transmission Electron Microscopy group has two main objectives: (i) epitaxial thin film deposition and (ii) in-situ TEM tensile experiments.

In the first part of the project, we are developing reproducible method for epitaxial growth of thin metal films by Molecular Beam Epitaxy. To favor preferred orientation and subsequently to induce specific defects and/or grain boundaries, we introduced various substrates, currently single crystal NaCl and mica polymorphs, capable of inducing [001]Cu and [111]Cu epitaxial growth, respectively. After determining the crystallographic relations between the substrates and the as-deposited metal thin films, we will expand the project with depositing nanocrystalline, metastable compounds such as CuCr or CuFe, exhibiting superior combination of high thermal and electrical conductivity, high strength and long-term stability. The micro- and nanostructure of these compounds will be characterized by aberration-corrected TEM and STEM.

In the second part of the project, we will perform in-situ mechanical deformation in the TEM on the pre-characterized thin films, using a TEM sample straining holder. The expected results facilitate insights into the nano-structural characterization of materials on the atomic level and the correlation with their nano-scale mechanical behavior, providing valuable guidelines for microstructural design of materials.