A5036748511- Ferroelectric and Piezoelectric Materials
- Multiferroics and related materials
- Acoustic Wave Resonator Technologies
- Dielectric materials and actuators
- Magnetic and transport properties of perovskites and related materials
- Liquid Crystal Research Advancements
- Thermal properties of materials
- Rare-earth and actinide compounds
- Magnetic properties of thin films
- Iron-based superconductors research
- Dielectric properties of ceramics
- Glass properties and applications
- Advanced Sensor and Energy Harvesting Materials
- Underwater Acoustics Research
- Microwave Dielectric Ceramics Synthesis
- Advanced Thermoelectric Materials and Devices
- Polymer Nanocomposites and Properties
- Magnetic Field Sensors Techniques
- Thermal Expansion and Ionic Conductivity
- Copper-based nanomaterials and applications
- nanoparticles nucleation surface interactions
- Phase-change materials and chalcogenides
- Advanced ceramic materials synthesis
- Photonic Crystals and Applications
- ZnO doping and properties
Luxembourg Institute of Science and Technology
2021-2024
Technical University of Denmark
2024
University of Connecticut
2015-2023
Czech Academy of Sciences
2018-2020
Czech Academy of Sciences, Institute of Physics
2018-2020
London Rebuilding Society
2018
Abstract Chirality, an intrinsic handedness, is one of the most intriguing fundamental phenomena in nature. Materials composed chiral molecules find broad applications areas ranging from nonlinear optics and spintronics to biology pharmaceuticals. However, chirality usually invariable inherent property a given material that cannot be easily changed at will. Here, we demonstrate ferroelectric nanodots support skyrmions which can controlled switched. We devise protocols for realizing control...
In this work we use a phenomenological theory of ferroelectric switching in <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:msub><a:mtext>BiFeO</a:mtext><a:mn>3</a:mn></a:msub></a:math> thin films to uncover the mechanism two-step process that leads reversal weak magnetization these materials. First, introduce realistic model <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:msub><b:mtext>BiFeO</b:mtext><b:mn>3</b:mn></b:msub></b:math> film, including Landau energy isolated...
Composite materials comprised of ferroelectric nanoparticles in a dielectric matrix are being actively investigated for variety functional properties attractive wide range novel electronic and energy harvesting devices. However, the dependence these functionalities on shapes, sizes, orientation mutual arrangement particles is currently not fully understood. In this study, we utilize time-dependent Ginzburg-Landau approach combined with coupled-physics finite-element-method based simulations...
The dependence of the polarization texture topology in ferroelectric PbTiO3 nanoparticles, embedded a dielectric matrix, on particle shape and size was investigated with time-dependent Landau-Ginzburg-Devonshire approach combined coupled-physics finite-element-method based simulations. Particle shapes belonging to superellipsoidal family were probed, including octahedral, cubic, intermediate geometries. For each shape, parametric sweep sizes ranging from 2 40 nm conducted, revealing general...
Abstract Solid-state electrothermal energy interconversion utilising the electrocaloric effect is currently being considered as a viable source of applications alternative to contemporary cooling and heating technologies. Electrocaloric performance dielectric system critically dependent on number uncorrelated polar states, or ‘entropy channels’ present within phase space. Exact physical origins these states are unclear practical methodologies for controlling their creating additional ones...
We report a comprehensive set of density functional theory calculations on the family layered antiferromagnetic manganese pnictides $(\mathrm{Ba},\mathrm{Ca},\mathrm{Sr}){\mathrm{Mn}}_{2}{(\mathrm{P},\mathrm{As},\mathrm{Sb})}_{2}$. characterize all components to linear magnetoelectric (ME) tensor $\ensuremath{\alpha}$, which are parsed into their contributions from spin and orbital moments for both lattice-mediated clamped-ion electronic analogs. Our main results show that magnetization...
Using a free-energy based computational model, we have investigated the response of system comprising two interacting ferroelectric nanospheres, embedded in dielectric medium, to static external electric field. The is hysteretic and tunable by changing inter-particle distance orientation applied field, which strongly modulates field-driven long-range elastic interactions between particles that propagate through matrix. At small separations, sensitivity behavior with respect field direction...
Ferroelectric-dielectric composite materials are attractive for a range of applications in future functional devices. Here, we utilized free energy based computational approach to investigate the electric-field driven response isolated ferroelectric nanoparticles embedded dielectric matrix and its dependence on particle size, shape, orientation applied field E. Particle shapes belonging superellipsoidal family were considered, including octahedral, spherical, cuboidal structures, as well...
The ferroelectric domain pattern within lithographically defined PbTiO3/SrTiO3 ferroelectric/dielectric heteroepitaxial superlattice nanostructures is strongly influenced by the edges of structures. Synchrotron x-ray nanobeam diffraction reveals that spontaneously formed 180{\deg} stripe domains exhibited such superlattices adopt a configuration in rectangular which walls are aligned with long patterned edges. angular distribution diffuse scattering intensity from nanodomains indicates an...
A collective excitation of the spin structure in a magnetic insulator can transmit spin-angular momentum with negligible dissipation. This quantum wave, introduced more than nine decades ago, has always been manipulated through dipoles, (i.e., timereversal symmetry). Here, we report experimental observation chiral-spin transport multiferroic BiFeO3, where is controlled by reversing ferroelectric polarization spatial inversion The ferroelectrically magnons produce an unprecedented ratio up to...
Nanoparticles, particularly core-shell nanoparticles (CSNPs), offer a wide palette of customizable properties unlike those their bulk counterparts. Here finite-element modeling shows how the size, morphology, and composition semiconducting CSNP can be tailored to tune its optical properties. Large misfit strains are created at interface core shell, yielding distribution values for band gap throughout shell volume---a phenomenon that could used engineer solar cells or photocatalysts, example.
Interfacial phenomena in dielectric-ferroelectric composites have significant potential for promoting novel properties. Here, we utilize a dynamic Landau–Ginzburg–Devonshire methodology to elucidate the influence of an electrostatic self-interaction on polarization behavior spherical ferroelectric nanoparticles embedded dielectric matrix. By varying particle volume and permittivity surrounding medium, phase boundaries between states with patterns exhibiting monodomains, structural,...
The transparent conducting oxide ZnO is one of the most versatile materials for nanoscale applications, and can be shaped into a variety structures. Here finite-element modeling used to characterize band-gap changes induced by elastic distortions in monolithic nanowires, obtaining good agreement with experiments. Zn-ZnO core-shell nanowires are also proposed as an attractive optoelectronic system, their size, shape, morphology optimized maximum downshifts.
A continuum approach to study magnetoelectric multiferroic ${\mathrm{BiFeO}}_{3}$ (BFO) is proposed. Our modeling effort marries the ferroelectric (FE) phase field method and micromagnetic simulations describe entire order parameter sector (polarization, oxygen antiphase tilts, strain, magnetism) self-consistently on same time- length scale. In this paper, we discuss our choice of FE magnetic energy terms demonstrate benchmarks against known behavior. We parametrize lowest couplings...
We apply density functional theory to explore the magnetoelectric (ME) properties of two-dimensional $\mathrm{Nb}_3\mathrm{(Cl,Br,I)}_8$. These compounds have recently been proposed exhibit coupled ferroelectric and ferromagnetic order leading a switchable anomalous valley Hall effect (AVHE). Using both spin-spiral self-consistent spin-orbit calculations, we predict an in-plane $120^\circ$ cycloid trimerized spins as ground state for $\mathrm{Nb}_3\mathrm{Cl}_8$. For...
We report a comprehensive set of density functional theory calculations on the family layered antiferromagnetic manganese pnictides (Ba, Ca, Sr)$\mathrm{Mn}_2\mathrm{(P, As, Sb)}_2$. characterize all components to linear magnetoelectric (ME) tensor $\alpha$ which are parsed into their contributions from spin and orbital moments for both lattice-mediated clamped-ion electronic analogs. Our main results show that magnetization cannot be neglected in these systems. The ME response is dominated...
BaTiO$_3$ (BTO) is a prototypical perovskite ferroelectric, whose dielectric permittivity and loss spectra -- which are strongly temperature frequency dependent include contributions from inhomogeneous polarization patterns, with polar domain walls (DWs) being the most common types. In order to elucidate how DWs influence response, we utilized continuum approach based on Landau-Ginzburg theory model field-dependent properties of polydomain tetragonal phase BTO near room above. A system...
In this work we use a phenomenological theory of ferroelectric switching in BiFeO$_3$ thin films to uncover the mechanism two-step process that leads reversal weak magnetization these materials. First, introduce realistic model film, including Landau energy isolated domains as well constraints account for presence substrate and multidomain configuration found experimentally. We obtain statistical information about behavior - by running dynamical simulations based on Landau-Khalatnikov...
The solid solution Ba1−xSrxTiO3 (BSTO) displays dielectric response that is highly tunable, while also exhibiting low losses in a broad frequency regime, including the microwave band. Therefore, there need for better understanding of influence BSTO microstructure on its relaxor properties and performance variety technological applications. Since local polarization strongly dependent composition, so to an applied AC field. In this work, we have adopted phase field method study...