A5055274871- Multiferroics and related materials
- Ferroelectric and Piezoelectric Materials
- Magnetic and transport properties of perovskites and related materials
- Advanced Condensed Matter Physics
- Acoustic Wave Resonator Technologies
- Liquid Crystal Research Advancements
- Ferroelectric and Negative Capacitance Devices
- Material Dynamics and Properties
- Dark Matter and Cosmic Phenomena
- Astrophysics and Cosmic Phenomena
- Thermal Expansion and Ionic Conductivity
- Atmospheric Ozone and Climate
- Underwater Acoustics Research
- Shape Memory Alloy Transformations
- Gamma-ray bursts and supernovae
- Chemical and Physical Properties of Materials
- Semiconductor materials and devices
- Seismic Waves and Analysis
- Railway Engineering and Dynamics
- Ultrasonics and Acoustic Wave Propagation
Luxembourg Institute of Science and Technology
2020-2024
Institute of Physics Rosario
2014-2020
Consejo Nacional de Investigaciones Científicas y Técnicas
2010-2020
National University of Rosario
2013-2016
Pierre Auger Observatory
2010
Instituto de Ciências Farmacêuticas
2010
National University of General San Martín
2010
Servicio Geológico Minero Argentino
2010
Nanostructured ferroelectrics display exotic multidomain configurations resulting from the electrostatic and elastic boundary conditions they are subject to. While ferroelectric domains appear frozen in experimental images, atomistic second-principles studies suggest that may become spontaneously mobile upon heating, with polar order melting a liquidlike fashion. Here, we run molecular dynamics simulations of model systems (PbTiO_{3}/SrTiO_{3} superlattices) to study unique features this...
The structural and polar properties of $\mathrm{BiFe}{\mathrm{O}}_{3}$ at finite temperature are investigated using an atomistic shell model fitted to first-principles calculations. Molecular dynamics simulations show a direct transition from the low-temperature $R3c$ ferroelectric phase Pbnm orthorhombic without evidence any intermediate bridging between them. high-temperature is characterized by presence two sublattices with opposite polarizations, it displays characteristic...
Ferroelectrics subject to suitable electric boundary conditions present a steady negative capacitance response. When the ferroelectric is in heterostructure, this behavior yields voltage amplification other elements, which experience potential difference larger than one applied, holding promise for low-power electronics. So far research has focused on verifying effect and little known about how optimize it. Here we describe an electrostatic theory of ferroelectric/dielectric superlattices,...
In this work we study, by means of ab initio calculations, the structural, electronic and magnetic properties Y-doped BiFeO3 compounds. We determine that there is a morphotropic phase boundary at an yttrium concentration [Formula: see text], where structure changes from R3c to Pnma. This structural transition driven chemical pressure induced dopant. By analyzing evolution oxygen octahedral tilts find enhanced antiferrodistortive distortion when increasing Y-doping, together with reduction...
Abstract The electrocaloric effect, that is, the temperature change experienced by an insulator upon application of electric field, offers promising ecofriendly alternatives to refrigeration. However, theoretical treatments this response are mostly case specific and lack a unified picture revealing similarities differences among various known effects. Here, we show effect lends itself straightforward interpretation when expressed as Taylor series in external field. Our formalism explains...
The effect of high tensile strain and low dimensionality on the magnetic electronic properties $\mathrm{Ca}\mathrm{Mn}{\mathrm{O}}_{3}$ ultrathin films, epitaxially grown $\mathrm{Sr}\mathrm{Ti}{\mathrm{O}}_{3}$ substrates, are experimentally studied theoretically analyzed. By means ab initio calculations, we find that both produced by substrate presence free surface contribute to stabilization an in-plane ferromagnetic coupling, giving rise a nonzero net moment in films. Coupled with this...
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...
Structural and thermal properties of $\mathrm{BiFe}{\mathrm{O}}_{3}$ under compressive epitaxial strain are investigated using a shell model fitted to first-principles calculations. We show that developed for the bulk describes properly behavior compound as function strain, including appearance tetragonallike phase with large $c/a$ ratio. The obtained temperature-strain diagram reproduces several features observed experimentally in thin films. Molecular dynamic simulations morphotropic...
Ferroelectrics under suitable electric boundary conditions can present a negative capacitance response, whereby the total voltage drop across ferroelectric opposes externally applied bias. When is in heterostructure, this behavior yields amplification other elements, an effect that could be leveraged low-power electronic devices. Interestingly, mentioned should have accompanying elastic effect. Specifically, typical case materials contact with are non-polar dielectrics, those enhanced...
This paper analyzes a peculiar phenomenon of non-reciprocal domain wall pairs and illustrate the implications in ab-initio-based atomistic computational experiments with (112)-oriented planar R180 walls within canonical multiferroic ferroelectric crystal BiFeO3. Results show that parallel on opposite sides given simply twinned lamellar structure can have considerably different polarization oxygen octahedra tilt profiles, thickness energy densities. The spontaneous formation zigzag triangular...
This paper analyzes how the ferroelectric properties of cubic-like BiFeO$_3$ nanoparticles are affected by different terminations and charge distributions at surface using ab-initio-based atomistic computational experiments. Our findings unveil multiple multidomain configurations illustrate order parameters evolve towards surface. Interestingly, for neutral terminations, a non-rhombohedral phase with stripe-like polarization arrangement was stabilized. We evaluate polarization, oxygen...
Nanostructured ferroelectrics display exotic multidomain configurations resulting from the electrostatic and elastic boundary conditions they are subject to. While ferroelectric domains appear frozen in experimental images, atomistic second-principles studies suggest that may become spontaneously mobile upon heating, with polar order {\sl melting} a liquid-like fashion. Here we run molecular dynamics simulations of model systems (PbTiO$_3$/SrTiO$_3$ superlattices) to study unique features...
Abstract We develop a first-principles atomistic shell model for BiFeO3to study its ferroelectric and structural properties at finite temperature. The parameters of the potential are adjusted to reproduce results in different relevant configurations. Molecular dynamics simulations show that resulting is able describe ground-state R3c structure which remains stable as temperature increases. At about 1100 K, system displays first-order phase transition paraelectric Pbnm phase. Our indicate...
The mechanocaloric effect is the temperature change of a material upon application or removal an external stress. Beyond its fundamental interest, this caloric response represents promising and ecofriendly alternative to current cooling technologies. To obtain large effects, we need materials whose elastic properties (e.g., strain, compliance) are strongly dependent. This case ferroelectric perovskite oxides, where development spontaneous electric polarization accompanied by significant...
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 in order describe entire parameter sector (polarization, oxygen antiphase tilts, strain, magnetism) self-consistently on same time length scale. In this paper, we discuss our choice of magnetic energy terms demonstrate benchmarks against known behavior. We parameterize lowest couplings structural...
We applied the PIXE (Particle‐Induced X‐ray Emission) technique to samples of atmospheric aerosols collected in filters Auger South Observatory, Malargüe, Argentina, with instrument Andersen Graseby 240. analyzed concentration PM2.5, PM2.5–10 and PM10 by gravimetric analysis elemental composition fine (size <2.5 μm) coarse between 2.5 μm 10 particles technique. complemented study microscopic analysis, SEM/EDX. discuss levels region, which general are very low. focus our winter spring...
We show that the electrocaloric (EC) effect -- e.g., temperature change experienced by an insulator upon application of electric bias lends itself to a straightforward interpretation when expressed as Taylor series in external field. Our formalism explains unified and simple way most notable small-field effects reported literature so-called {\em normal} (increase under bias, usually found ferroelectrics) inverse} (decrease temperature, e.g. antiferroelectrics) EC responses clarifies their...