Magnetic nanocaps, formed by depositing Co/Pd multilayers on highly ordered arrays of silica nanospheres, present a promising area of study due to their unique properties. This research focuses on fabricating and characterizing these nanocaps and comparing them to films deposited on flat silicon substrates. Using an advanced drop-casting method, we prepared two-dimensional arrays of silica...
The discovery of the topological phases of matter sparked a renaissance in solid-state physics, however the broader applications to materials engineering are still in their infancy. The three-dimensional topological insulators offer a particularly simple new paradigm for developing unique functionality which relies on exploiting surfaces and interfaces via nanoarchitectural design.
I will...
An increasing number of studies are showing the possibility of tuning the electronic properties of functional materials via an unconventional dopant: hydrogen. In correlated oxide interfaces, and especially in rare-earth nickelates, hydrogen-induced reversible electronic and structural phase transitions have been uncovered [1-2]. Neutron and x-ray scattering methods are without doubt one of...
Investigating the magnetism at interfaces with designed periodic modulation of the magnetization—known as magnetic metamaterials—has recently gained significant attention [1]. Such structures provide platforms for fundamental studies of order and dynamics at the mesoscale, as well as having potential applications such as computation [2]. The magnetism in these materials can be studied by real...
Pt/Co/Pt and Pd/Co/Pd heterostructures with perpendicular magnetic anisotropy (PMA) are traditionally used for magnetic recording to achieve high magnetic data storage density. PMA can be tuned by e.g. thin film thickness, strain, ion bombardment or temperature. Recently, it has been shown that the absorption of hydrogen in the heavy metal modifies the interfacial spin-orbit coupling and hence...
The coexistence of different order parameters can lead to exotic new quantum phenomena. In hard condensed matter materials, their interplay often generates magnetic chiral structures with correlations on the nanometer and mesoscopic length scale, which can be explored by polarization-analyzed Small-Angle-Neutron-Scattering (SANS) in bulk systems, and by its surface-sensitive counterpart...
Polarized neutron reflectometry (PNR) offers the possibility to resolve structural and magnetic morphologies of heterostructures and their interfaces as a function of depth with sub-nm resolution. In addition, lateral structures such as magnetic domains in the $\mu$m scale are accessible with off-specular scattering. This talk discusses two examples of functional thin films in which the...
Thin film heterostructures are essential in modern device development, offering a platform for manipulating interfacial effects. Molecular Beam Epitaxy (MBE) is an indispensable technique for the growth of high-quality epitaxial films, heterostructures, and nanostructures. It enables precise control over the composition, thickness, and structure of materials and has led to the discovery of a...
Controlled oxygen release or uptake in complex oxides can induce changes of the crystal structure and simultaneously of the magnetic and electrical properties. Consequently, a systematic control of the oxygen stoichiometry can enable potential applications in spintronics, solid oxide fuel cells and catalysts. In La0.6Sr0.4CoO3-δ (LSCO) the gradual oxygen release triggers a phase transition...
The Fe$_3$O$_4$/Nb:STO system has gathered significant attention due to its potential application in spintronics and memristors. The interface between Fe$_3$O$_4$ and Nb:STO plays a crucial role in determining the overall electronic and magnetic properties of the system. We present an investigation of a 30 nm Fe$_3$O$_4$ thin film on a TiO$_2$ terminated Nb-doped SrTiO$_3$ (TiO$_2$-Nb:STO)...
