A5055401106- Ferroelectric and Piezoelectric Materials
- Multiferroics and related materials
- Acoustic Wave Resonator Technologies
- Magnetic and transport properties of perovskites and related materials
- Force Microscopy Techniques and Applications
- Electronic and Structural Properties of Oxides
- Nanofabrication and Lithography Techniques
- Adhesion, Friction, and Surface Interactions
- Dielectric properties of ceramics
- Nanowire Synthesis and Applications
- Microwave Dielectric Ceramics Synthesis
- Anodic Oxide Films and Nanostructures
- Semiconductor materials and devices
- Metal and Thin Film Mechanics
- Photonic and Optical Devices
- Ultrasonics and Acoustic Wave Propagation
- Quantum Dots Synthesis And Properties
- Magneto-Optical Properties and Applications
- Perovskite Materials and Applications
- Advanced Condensed Matter Physics
- Photorefractive and Nonlinear Optics
- ZnO doping and properties
- Material Dynamics and Properties
- Transition Metal Oxide Nanomaterials
- 2D Materials and Applications
Institut National de la Recherche Scientifique
2014-2023
Varian Medical Systems (Switzerland)
2017
Centre National pour la Recherche Scientifique et Technique (CNRST)
2007-2016
Université du Québec
2016
Université du Québec à Montréal
2007
Max Planck Institute of Microstructure Physics
1998-2005
Max Planck Society
1999-2004
Alexandru Ioan Cuza University
1996-2000
Institute of Magnetism
1996
Theoretical models for small ferroelectric particles predict a progressive decrease of the Curie temperature, spontaneous lattice strain, and polarization until critical size corresponding to transition cubic phase disappearance ferroelectricity is reached. In contrast, behavior nanocrystalline $\mathrm{Ba}\mathrm{Ti}{\mathrm{O}}_{3}$ ceramics with grain $\ensuremath{\approx}30\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ dominated by extrinsic effects related boundaries which mask expected...
We report a large photovoltaic (PV) effect in multiferroic Bi2FeCrO6 (BFCO) films under monochromatic illumination at 635 nm with an intensity of 1.5 mW cm−2. These exhibit photocurrent zero bias voltage and open-circuit about 0.6 V. A high PV power conversion efficiency 6% for red light is achieved attributed to degree B-site cationic ordering between Fe Cr sublattices, the tuning which likely play key role further improvements properties BFCO.
Abstract Conversion of clean solar energy to chemical fuels is one the promising and up-and-coming applications metal–organic frameworks. However, fast recombination photogenerated charge carriers in these frameworks remains most significant limitation for their photocatalytic application. Although construction homojunctions a solution, it very challenging synthesize them. Herein, we report well-defined hierarchical homojunction based on via facile one-pot synthesis route directed by hollow...
Piezoresponse scanning force microscopy measurements performed on lead zirconate titanate mesoscopic structures revealed a negative shift of the initial piezoelectric hysteresis loop. The is dependent size structure and most probably due to pinning ferroelectric domains at free lateral surface ferroelectric–electrode interface. Considering simple model, thickness pinned domain layers found be about 15 70 nm interface surface, respectively.
Dense BaTiO3 ceramics with 50 nm average grain size obtained by spark plasma sintering were investigated. The dielectric data show a broad ferro–para phase transition maximum permittivity of at 390 K and 1 kHz. local ferroelectric switching behaviour was investigated piezoresponse force microscopy. Typical piezoelectric hysteresis loops recorded different positions the sample. present results provide experimental evidence for polarization scale, indicating that critical disappearance in...
Lead zirconate titanate nanoislands were obtained by a self-patterning method making use of the instability ultrathin films during high-temperature treatments. After annealing, as-deposited film breaks into islands with narrow size distribution. The single-crystal studied scanning and high-resolution transmission electron microscopy, atomic force x-ray diffraction. They show an epitaxial relationship Nb-doped (001) SrTiO3 substrate. ferroelectric switching several individual was investigated...
Multiple NaNbO3 nanoplates are created within Nb2O5 nanotubes forming a unique class of heterostructure combining ferroelectric and semiconducting nanomaterials. Local piezoelectric studies on show clear behavior (see figure), while the semiconductive properties host allows for switching electrical conductivity by an external electric field.
A detailed analysis of polarization reversal in ferroelectrics has been performed, the framework Landau model for phase transitions. Some important characteristics homogeneous switching have emphasized and later used studying more general case inhomogeneous switching. The two extremes current correspond to inflexion points dielectric hysteresis loop. Hysteresis loops poled ferroelectric samples are expected include negative-susceptibility regions, high-frequency applied electric fields....
A study of the frequency dependence signal in piezoresponse scanning force microscopy ferroelectric materials has been performed. It is found that, for soft cantilevers, governed by cantilever elastic properties. Both ferroelectric-electromechanical and electrostatic interaction contributions to overall were depend on testing voltage. Indications optimal measurement regimes are given.
In this letter, we report on the switching properties of an ordered system Bi4Ti3O12 ferroelectric memory cells average lateral size 0.18 μm formed via a self-assembling process. The ferroelectricity these has been measured microscopically and it demonstrated that individual cell is switching. Switching single nanoelectrode was achieved scanning force microscopy working in piezoresponse mode.
Arbitrary patterns of heteroepitaxial multiferroic Bi2FeCrO6 nanostructures are fabricated by pulsed laser deposition using a simple nanostencil approach. The crystal orientation and the shape epitaxial controlled niobium-doped SrTiO3 substrates. Using advanced characterization techniques, it is established that material retains its ferroelectric magnetic properties at room temperature even submicrometer dimensions.
The influence of the deposition pressure (PO2) and substrate temperature (TS) during growth Bi2FeCrO6 thin films grown by pulsed laser has been investigated. It is found that high volatility Bi makes very difficult pure on SrTiO3 substrates possible only in a narrow parameter window. We find phase formed within window around an oxygen PO2=1.2×10−2 mbar TS=680 °C. At lower or higher pressure, Bi7.38Cr0.62O12+x (also called b∗Bi2O3) Bi2Fe4O9/Bi2(Fe,Cr)4O9+x phases are detected, while at...
The possible existence of a new kind ferroelectric order and the need to explore domain arrangement in nanostructures has stimulated an increasing activity on growth nanowires. In present study, single crystal BaTiO3 nanowires with tetragonal structure were obtained by original solid-state process using layered titania coated BaCO3 nanocrystals as reactive templates. Formation occurs at 700 °C topochemical reaction. Consequently, initial morphology is retained final product. Piezoresponse...
Spider silk is a fascinating natural composite material. Its combination of strength and toughness unrivalled in nature, as result, it has gained considerable interest from the medical, physics, materials communities. Most this attention focused on one to tens nanometer scale: predominantly primary (peptide sequences) secondary (β sheets, helices, amorphous domains) structure, with some insights into tertiary structure (the arrangement these structures) describe origins mechanical biological...
The p–i–n heterojunction devices based on intrinsic absorber multiferroic Bi<sub>2</sub>FeCrO<sub>6</sub> sandwiched between p-type NiO and n-type Nb-doped SrTiO<sub>3</sub> were demonstrated.