A5028496095- Iron oxide chemistry and applications
- Magnetic Properties and Synthesis of Ferrites
- Advancements in Battery Materials
- Characterization and Applications of Magnetic Nanoparticles
- Advanced Battery Materials and Technologies
- Magnetic properties of thin films
- Theoretical and Computational Physics
- Advanced Battery Technologies Research
- Fluid Dynamics and Thin Films
- Geomagnetism and Paleomagnetism Studies
- nanoparticles nucleation surface interactions
- Advanced battery technologies research
- Material Dynamics and Properties
- Speech and dialogue systems
- Magnetic and Electromagnetic Effects
- Phase Equilibria and Thermodynamics
- Covalent Organic Framework Applications
- Natural Language Processing Techniques
- Advanced Computational Techniques and Applications
- Educational Technology and Assessment
- Multi-Agent Systems and Negotiation
- Diamond and Carbon-based Materials Research
- Catalysis and Oxidation Reactions
- Metal-Organic Frameworks: Synthesis and Applications
- Additive Manufacturing Materials and Processes
University of Illinois Chicago
2023-2025
Argonne National Laboratory
2023-2025
Sorbonne Université
2000-2024
Institut Systèmes Intelligents et de Robotique
2024
Centre National de la Recherche Scientifique
1999-2010
Laboratoire de Chimie Bactérienne
2008
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2000-2004
Laboratoire de Réactivité de Surface
1999-2001
CEA Paris-Saclay
2000
Laboratoire de Chimie Moléculaire
2000
By controlling solvent evaporation rates, it has been possible to form micrometer rings and hexagonal arrays made of nanocrystals different sizes, shapes materials. Such patterns are driven by surface tension gradients that induce Bénard−Marangoni instabilities in the liquid films. The resulting self-assembled structures consistent with theoretical prediction hydrodynamic instabilities.
The magnetic properties of nonstoichiometric cobalt ferrite nanocrystals differing by their sizes were investigated measurements and Fe57 Mössbauer spectroscopy. We found that the spin-wave Bloch exponent increases with increasing particle size, in agreement previous studies. Under a field 7 T, we observed partial reorientation two ferrimagnetic Fe3+ sublattice magnetizations towards direction size; discuss applicability an intrinsic spin canting model as function size. An evaluation...
In the present paper, it is demonstrated that by slow evaporation on a substrate of ferrofluid made maghemite nanocrystals, in an applied magnetic field, nanocrystals are organized ribbons. The magnetization easy axes partially oriented. orientation strongly depends strength field used during deposition process.
The origin of the magnetic anisotropy is explained in an assembly aligned nanoparticles. For that, nanoparticles synthesized biologically by Magnetospirillum magneticum AMB-1 magnetotactic bacteria are used. first time, it possible to differentiate between two contributions arising from alignment magnetosome easy axes and strength dipolar interactions. shown arise mainly interactions magnetosomes.
Abstract Lithium‐air batteries based on CO 2 reactant (Li–CO ) have recently been of interest because it has found that reversible Li/CO electrochemistry is feasible. In this study, a new medium‐entropy cathode catalyst, (NbTa) 0.5 BiS 3 , enables the to operate at high rates presented. This medium entropy catalyst combined with an ionic liquid‐based electrolyte blend give Li–CO battery operates current density 5000 mA g −1 and capacity mAh for up 125 cycles, far exceeding reported values in...
The chemical pathway for synthesizing covalent organic frameworks (COFs) involves a complex medley of reaction sequences over rippling energy landscape that cannot be adequately described using existing theories. Even with the development state-of-the-art experimental and computational tools, identifying primary mechanisms nucleation growth COFs remains elusive. Other than empirically, little is known about how catalyst composition water activity affect kinetics pathway. Here, first time, we...
Ferrite nanocrystals have been synthesized by use of functionalized surfactantsto give nanoparticles doped with 3.5 % in mass cobalt ions. These can be aligned on a substrate very large scale when the particles are deposited presence magnetic field (see Figure). In absence an applied field, self-assemble into spheres.
Li-CO$_2$ batteries show promise as energy storage solutions, offering high theoretical density and CO$_2$ fixation. Their performance relies on the formation decomposition of Li$_2$CO$_3$/C during discharge charge cycles, respectively. We used a multiscale modeling framework that integrates Density Functional Theory (DFT), Ab-Initio Molecular Dynamics (AIMD), classical (MD), Finite Element Analysis (FEA) to investigate atomic cell-level properties. The battery consists lithium metal anode,...
Maghemite nanocrystals, deposited by slow evaporation on HOPG (highly oriented pyrolytic graphite) substrate, form mesoscopic structures which strongly depend the nanocrystal coating. When coating consists of citrate ions and octanoic acid, tubelike are formed when deposition process takes place under an applied magnetic field. Conversely, dense films nanocrystals coated with propanoic acid dodecanoic acid. The behaviors markedly differ organization attributed to change in anisotropy...
We report structural characterization and magnetic properties of various assemblies chains magnetosomes. The same are observed for the magnetotactic bacteria extracted magnetosomes isolated in a polymer. When form denser structure than that bacteria, change markedly. A decrease coercivity reduced remanence is observed. This behavior attributed to an enhancement dipolar interactions between limit weakly interacting system; is, magnetostatic energy lower anisotropy energy. effect more...
Mesoscopic structures made of cigar-shaped γ-Fe2O3 nanocrystals with an average length 325 nm and aspect ratio 7 are described. The were prepared starting from aqueous solution to which a magnetic field parallel the substrate could be applied during evaporation process. If was applied, rotated their long axis along direction form ribbons, whereas without remained deposited on random orientation. orientation is responsible for anisotropy ribbons as evidenced by hysteresis loops.
In this letter, we show that the use of nanocrystals enables new insights into scaling law crack patterns. Directional and isotropic patterns made γ-Fe2O3 follow same law, with film height varying by 3 orders magnitude. A simple two-dimensional computer model for elastic fracture also leads to behavior directional cracks, in good agreement experiments.
Cracks due to a shrinking film restricted by adhesion surface are observed in nature at various length scales ranging from tiny crack segments nanoparticle films enormous domains the earth's crust. Here, we study formation of cracks magnetic made maghemite (gamma-Fe2O3) nanocrystals. The oriented an external field applied during drying process which presents new method produce directional patterns. It is shown that and isotropic patterns follow same universal scaling law with height varying...
Abstract Optical microscopy on the machined surfaces of 4-point bend fatigue samples 3D printed in Ti-6Al-4V is used to characterize pores larger than ≈15 microns. A large enough number distinct scan speeds and tests that span process window provides a statistically useful dataset. The variation stress at which runouts (to 10 million cycles) are observed anti-correlated with pore density same inverse relationship exists for maximum size within area exposed tensile each test. Total life also...
Here, we show that cracks give valuable information on the height and isotropy of nanocrystal films. Two-dimensional crack patterns are systematically studied by simulations experiments varying anisotropy applied stress. The carried out using a bundle-spring network model, which allows studying influence patterns. For experiments, model system made magnetic γ-Fe2O3 nanocrystals is used, enables change in stress applying field during drying process. pattern morphology investigated square,...
Solid structures made of collapsed cylinders organized in hexagonal, stripes and wavy line-like are fabricated by slow evaporation maghemite nanocrystals dispersed hexane subjected to an applied field perpendicular the substrate. The sizes experimental well described a theory based on minimization total free energy. Comparison between experiment shows that explained labyrinthine instability enabled colloidal liquid−gas phase transition during process. From theoretical model data, it is...
The efficacy of electrolytes significantly affects battery performance, leading to the development several strategies enhance them. Despite this, understanding solvation structure remains inadequate. It is imperative understand structure–property–performance relationship using diverse techniques. This review explores recent advancements in electrolyte design for high capacity, high-voltage, wide-temperature, fast-charging, and safe applications. To begin, current state-of-the-art directions...
Accurate determination of the electronic properties correlated oxides remains a significant challenge for computational theory. Traditional Hubbard-corrected density functional theory (DFT+U) frequently encounters limitations in precisely capturing electron correlation, particularly predicting band gaps. We introduce systematic methodology to enhance accuracy diffusion Monte Carlo (DMC) simulations both ground and excited states, focusing on LiCoO