Magnetic and transport properties of thin uranium-based films engineered by strain


Strain engineering has emerged as a powerful tool to tune physical properties of materials. It is typically realized through the choice of substrate which imposes its lattice parameter onto the film and can arise either during film growth and/or due to thermal expansion mismatch. Strain mimics application of pressure, the common means to manipulate the electronic structure of bulk materials, but in contrast to pressure, it can be negative. By using various substrates, strained thin films of identical chemical formulas that have dramatically different electronic and magnetic properties can be created. This is especially important for materials that are in proximity to various instabilities (magnetic and/or structural). The latter are usually very sensitive to the changes of extrenal conditions, such as temperature, magnetic field or pressure. The latter, compressive or expansive, can serve as a driving force towards (or further away) from the instability. The essence of the work is preparation, studies of crystal structure and physical properties of selected thin films based on uranium. The exaple is a non-conventional superconductor UTe2, which is close to the magnetic ordering connected to the 5f electron states of uranium. A wide range of macro- and microspopic methods (XPS, XRD, TEM, RBS, SQUID) and ab initio calculations will be used for understanding the structure-properties relationship. The aim is to master the state of material (magnetic and/or superconducting) by choosing a suitable substrate.

The work is suitable to candidates with a M.Sc. degree in Phyics or Chemistry. Knowledge of the Solid State Physics and basic knowledge of English is essential. Knowlegde of x-ray diffraction methods is beneficial.