A5034455870- Multiferroics and related materials
- Ferroelectric and Piezoelectric Materials
- Electronic and Structural Properties of Oxides
- Acoustic Wave Resonator Technologies
- Advanced Condensed Matter Physics
- Magnetic properties of thin films
- Advanced Memory and Neural Computing
- Electron and X-Ray Spectroscopy Techniques
- Smart Materials for Construction
- Force Microscopy Techniques and Applications
- Ion-surface interactions and analysis
- Nanocluster Synthesis and Applications
- Mechanical Behavior of Composites
- Silicon and Solar Cell Technologies
- Non-Destructive Testing Techniques
- Innovations in Concrete and Construction Materials
- Cultural Heritage Materials Analysis
- Advanced Materials Characterization Techniques
- Metal Forming Simulation Techniques
- Quantum Dots Synthesis And Properties
- Carbon and Quantum Dots Applications
- Theoretical and Computational Physics
- Magnetic and transport properties of perovskites and related materials
- Advanced Surface Polishing Techniques
- Semiconductor materials and devices
Norwegian University of Science and Technology
2019-2024
University of Kaiserslautern
1996
Ferroelectric domain walls are a completely new type of functional interface, which have the potential to revolutionize nanotechnology. In addition emergent phenomena at walls, they spatially mobile and can be injected, positioned, deleted on demand, giving degree flexibility that is not available conventional interfaces. Progress in field closely linked development modern microscopy methods, essential for studying their physical properties nanoscale. this article, we discuss scanning...
Layered oxides exhibit high ionic mobility and chemical flexibility, attracting interest as cathode materials for lithium-ion batteries the pairing of hydrogen production carbon capture. Recently, layered emerged highly tunable semiconductors. For example, by introducing anti-Frenkel defects, electronic hopping conductance in hexagonal manganites was increased locally orders magnitude. Here, we demonstrate local acceptor donor doping Er(Mn,Ti)O$_3$, facilitated splitting such defects under...
Ferroelectric domain walls are quasi-2D systems that show great promise for the development of nonvolatile memory, memristor technology, and electronic components with ultrasmall feature size. Electric fields, example, can change wall orientation relative to spontaneous polarization switch between resistive conductive states, controlling electrical current. Being embedded in a 3D material, however, not perfectly flat form networks, which leads complex physical structures. In this work,...
Abstract Extraordinary physical properties arise at polar interfaces in oxide materials, including the emergence of 2D electron gases, sheet‐superconductivity, and multiferroicity. A special type interface is ferroelectric domain walls, where electronic reconstruction phenomena can be driven by bound charges. Great progress has been achieved characterization such walls and, over last decade, their potential for next‐generation nanotechnology become clear. Established tomography techniques,...
A focused ion beam (FIB) methodology is developed to lift out suitable specimens containing charged domain walls in improper ferroelectric ErMnO3. The FIB procedure allows for extracting wall sections with well-defined charge states, enabling accurate studies of their intrinsic physical properties. Conductive atomic force microscopy (cAFM) measurements on a 700 nm thick lamella demonstrate enhanced electronic transport at consistent previous bulk measurements. correlation shown between...
Magnetic materials with competing magnetocrystalline anisotropy and dipolar energies can develop a wide range of domain patterns, including classical stripe domains, branching, topologically trivial nontrivial (skyrmionic) bubbles. We image the magnetic pattern ${\mathrm{Fe}}_{3}{\mathrm{Sn}}_{2}$ by force microscopy study its evolution due to geometrical confinement, fields, their combination. In lamellae thinner than 3 $\ensuremath{\mu}\mathrm{m}$, we observe domains whose size scales...
Focused ion beam (FIB) and scanning electron microscopy (SEM) are used to reversibly switch improper ferroelectric domains in the hexagonal manganite ErMnO3. Surface charging is achieved by local (positive charging) negative irradiation, which allows controlled polarization switching without need for electrical contacts. Polarization cycling reveals that domain walls tend return equilibrium configuration obtained as-grown state. The response of sub-surface studied FIB cross-sectioning,...
The research on topological phenomena in ferroelectric materials has revolutionized the way people understand polar order. Intriguing examples are skyrmions, vortex/anti-vortex structures, and incommensurabilties, which promote emergent physical properties ranging from electric-field-controllable chirality to negative capacitance effects. Here, impact of topologically protected vortices domain formation improper ErMnO3 polycrystals is studied, demonstrating inverted scaling behavior compared...
Abstract Intrinsically fluorescent carbon dots may form the basis for a safer and more accurate sensor technology digital counting in bioanalytical assays. This work presents simple inexpensive synthesis method producing embedded hollow silica particles. Hydrothermal treatment at low temperature (160 °C) of microporous particles presence urea citric acid results fluorescent, nanocomposites with surface area 12 m 2 /g. High absolute zeta potential (−44 mV) neutral pH demonstrates high...
Abstract Mit Hilfe des Strangpreßverfahrens lassen sich durch die Einlagerung von plättchenförmigen Teilchen aus hochfesten und hochmoduligen Werkstoffen in zu verpressende Glasschmelze Verbundstäbe mit im Vergleich zum unverstärkten Glas erhöhtem Elastizitätsmodul gesteigerter Festigkeit erzeugen. Diese Verbesserung der mechanischen Eigenschaften rührt erster Linie Ausrichtung Plättchen her, laminare Scherströmung hochviskosen Umformzone Matrizenkanal bewirkt wird. Um statistische Aussagen...
Ferroelectric domain walls are quasi-2D systems that show great promise for the development of non-volatile memory, memristor technology and electronic components with ultra-small feature size. Electric fields, example, can change wall orientation relative to spontaneous polarization switch between resistive conductive states, controlling electrical current. Being embedded in a 3D material, however, not perfectly flat form networks, which leads complex physical structures. We demonstrate...
Focused ion beam (FIB) and scanning electron microscopy (SEM) are used to reversibly switch improper ferroelectric domains in the hexagonal manganite ErMnO$_3$. Surface charging is achieved by local (positive charging) negative irradiation, which allows controlled polarization switching without need for electrical contacts. Polarization cycling reveals that domain walls tend return equilibrium configuration obtained as-grown state. The electric field response of sub-surface studied FIB...
Extraordinary physical properties arise at polar interfaces in oxide materials, including the emergence of two-dimensional electron gases, sheet-superconductivity, and multiferroicity. A special type interface are ferroelectric domain walls, where electronic reconstruction phenomena can be driven by bound charges. Great progress has been achieved characterization such walls and, over last decade, their potential for next-generation nanotechnology become clear. Established tomography...
A method to study Cellulose Nanofibril (CNF) distribution in three dimensions within a paper matrix-in-situ-was developed. Focused Ion Beam (FIB)/Scanning Electron Microscopy (SEM) tomography was used investigate the of cellulose nanofibres thee structure. Sufficient resolution and material contrast contained using both secondary back-scattered electrons volumes as large 103 um3. Challenges approaches achieve this are discussed, with respect microscopy technique image processing volume...
The research on topological phenomena in ferroelectric materials has revolutionized the way we understand polar order. Intriguing examples are skyrmions, vortex/anti-vortex structures and incommensurabilties, which promote emergent physical properties ranging from electric-field-controllable chirality to negative capacitance effects. Here, study impact of topologically protected vortices domain formation improper ErMnO3 polycrystals, demonstrating inverted scaling behavior compared classical...
Magnetic materials with competing magnetocrystalline anisotropy and dipolar energies can develop a wide range of domain patterns, including classical stripe domains, branching, as well topologically trivial non-trivial (skyrmionic) bubbles. We image the magnetic pattern Fe$_3$Sn$_2$ by force microscopy (MFM) study its evolution due to geometric confinement, fields, their combination. In lamellae thinner than 3 $μ$m, we observe domains whose size scales square root lamella thickness,...