Anotace
The possibility to create new materials bottom-up was enhanced via the stacking of atomically thin layers of two-dimensional (2D)
materials with van der Waals interactions (vdWIs). Unfortunately, the downside of vdWIs is the, in general, weak electronical and
mechanical interaction between the individual layers. This hinders the creation of multiferroic materials working at ambient conditions,
which are despite extensive research still very scarce, from stacked layers with vdWIs. This research aims to create a new 2D building
block: the 2D sandwich. This is a layered heterostructure with a strong interaction between the sandwich's individual layers mediated
via an ionic or multivalent bond, whereas the interaction with other layers is still solely due to the vdWIs. As the prototype functional
material, a 2D magnetoelectric multiferroic sandwich composed of layered transition metal chalcogenides, oxides or iodides will be
grown using the modulated elemental reactants method. To tackle the possible sample degradation in the sandwiches, ultra-high vacuum
optical surface science spectro-microscopy techniques will be developed to optically probe the 2D multiferroic sandwiches for both
magnetism, ferroelectricity and the coupling between them. The concept of open samples will be introduced, facilitating the scientific
community with the straightforward verification of the data and accelerate the development of this new class of 2D sandwiches. This
project will provide material design strategies that can remove the stringent lattice matching criteria to stack different classes of layered
materials and provide these class of layered materials with similar stacking freedom as layered materials with vdWIs. These insights
will allow the interbreeding of different classes of layered quantum materials, such as complex oxides, 2D layered crystals with vdWIs,
cuprate superconductors or topological insulators or semimetals.
