A5057249553- Advancements in Solid Oxide Fuel Cells
- Advanced ceramic materials synthesis
- Electronic and Structural Properties of Oxides
- Nuclear materials and radiation effects
- Ferroelectric and Piezoelectric Materials
- Catalytic Processes in Materials Science
- Fuel Cells and Related Materials
- Catalysis and Oxidation Reactions
- Microwave Dielectric Ceramics Synthesis
- Gas Sensing Nanomaterials and Sensors
- Magnetic and transport properties of perovskites and related materials
- Electrophoretic Deposition in Materials Science
- Advanced materials and composites
- Thermal Expansion and Ionic Conductivity
- Electrocatalysts for Energy Conversion
- Advanced Condensed Matter Physics
- Advanced Battery Materials and Technologies
- Chemical Looping and Thermochemical Processes
- Nuclear Materials and Properties
- ZnO doping and properties
- Physics of Superconductivity and Magnetism
- Pigment Synthesis and Properties
- Thermal and Kinetic Analysis
- Analytical Chemistry and Sensors
- Transition Metal Oxide Nanomaterials
Instituto de Pesquisas Energéticas e Nucleares
2008-2024
National Nuclear Energy Commission
2014-2024
Nuclear Engineering Institute
2010-2024
Universidade Federal do ABC
2017-2019
Centro Universitário da Cidade
2014
Microsoft (Brazil)
2014
Institut für Psychologische Psychotherapie
2008
Universidade Politecnica
1997
We have performed a detailed characterization of the magnetic properties Ni nanoparticles embedded in ${\mathrm{SiO}}_{2}$ amorphous matrix. A modified sol-gel method was employed which resulted particles with average radius $\ensuremath{\sim}3\mathrm{nm},$ as inferred by TEM analysis. Above blocking temperature ${T}_{B}\ensuremath{\approx}20\mathrm{K}$ for most diluted sample, magnetization data show expected scaling ${M/M}_{S}$ vs $H/T$ curves superparamagnetic particles. The hysteresis...
A brief overview is given of the main types and principles solid-state proton conductors with perovskite structure. Their properties are summarized in terms defect chemistry, transport chemical stability. good understanding these subjects allows manufacturing compounds desired electrical properties, for application renewable sustainable energy devices. few trends highlights scientific advances some classes protonic conductors. Recent results future prospect about also evaluated. The high...
We performed Synchrotron X-ray diffraction (XRD) analyses of internal residual stresses in monolithic samples a newly developed Li2O–Al2O3–SiO2 (LAS) glass–ceramic produced by sintering and commercial LAS glass–ceramic, CERAN®, the traditional crystal nucleation growth treatments. The elastic constants were measured instrumented indentation pulse-echo technique. thermal expansion coefficient virgilite was determined high temperature XRD dilatometry. c-axis contracts with increasing whereas...
This work brings insights into the defect chemistry of YBZ solid solutions by measuring enthalpies formation. We find a correlation between obtained thermodynamic data and known trend proton conductivity solutions. study is important for informed history-based materials selection processing specific applications.
The surface and interface enthalpies of cubic stabilized zirconia solid solutions containing 8, 10, 12 mol % Y2O3 were determined by a combination calorimetric, morphological, structural analyses techniques. Nanocrystalline samples with several areas degrees agglomeration synthesized simultaneous precipitation annealing at temperatures 470−900 °C. Samples characterized X-ray diffraction Raman spectroscopy. Surface measured N2 adsorption, estimated comparing from adsorption to those derived...
The proton transport properties of Nafion membranes were studied in a wide range temperature by using an air-tight sample holder able to maintain the hydrated at high relative humidity. conductivity continuously increased 40–180 °C with humidity kept RH = 100%. In 40–90 °C, followed Arrhenius-like thermal dependence. calculated apparent activation energy Ea values are good agreement via structural diffusion absorbed water. However, higher measuring temperatures upturn electrical was observed...
Abstract The main dielectric properties of several ceramic materials having niobium in their composition, proposed to take part 5G telecommunication devices, are reviewed. A preliminary basic presentation systems, the requirements for implementing use, a concise review compositions containing that have been studied thus far, and an evaluation performance detailed. survey is presented, including more than 80 different niobium, focusing on key parameters, such as constant, quality factor,...
Composite ceramic green pellets were prepared by attrition milling a mixture of (CeO2)0.8(Sm2O3)0.2 (samaria-doped ceria, SDC) powder and carbon nanotubes (CNTs), followed uniaxial isostatic pressing. The sintered inside dilatometer applying AC electric fields at 850 °C limiting the current to 1 A, achieving 20.2% final shrinkage. SDC samples reached 13.3% shrinkage under same conditions. Higher average grain sizes measured in specimens flash with CNTs. Impedance spectroscopy analyses show...
The dynamic magnetic properties of Ni nanoparticles diluted in an amorphous SiO2 matrix prepared from a modified sol-gel method have been studied by the frequency f dependence ac susceptibility \c{hi}(T). For samples with similar average radii ~ 3-4 nm, increase blocking temperature TB 20 to 40 K was observed for concentrations 1.5 and 5 wt.%, respectively, assigned effects dipolar interactions. Both in-phase \c{hi}'(T) out-of-phase \c{hi}"(T) maxima follow predictions thermally activated...
8 mol% Y2O3-stabilized ZrO2 (8YSZ) ceramics were prepared with KCl and LiF additions to obtain porous specimens high skeletal density. Thermogravimetric differential thermal analyses (TG/DTA) carried out on 8YSZ mixed 5 wt.% or as sacrificial pore formers that thermally removed during sintering. The melting evaporation of the alkali halides evaluated by analysis. Dilatometric analysis was also following same TG/DTA temperature profile results suggesting rearrangement particles melting....