A5050288134- Chalcogenide Semiconductor Thin Films
- Phase-change materials and chalcogenides
- Thermography and Photoacoustic Techniques
- Quantum Dots Synthesis And Properties
- X-ray Diffraction in Crystallography
- Advanced Thermoelectric Materials and Devices
- Food composition and properties
- Metallic Glasses and Amorphous Alloys
- Conducting polymers and applications
- High-pressure geophysics and materials
- Crystal Structures and Properties
- Electronic and Structural Properties of Oxides
- Semiconductor materials and interfaces
- 2D Materials and Applications
- Magnetic Properties of Alloys
- Polysaccharides Composition and Applications
- Solid-state spectroscopy and crystallography
- Heusler alloys: electronic and magnetic properties
- Transition Metal Oxide Nanomaterials
- Botanical Research and Applications
- Advanced Cellulose Research Studies
- Thermal properties of materials
- Proteins in Food Systems
- Thermodynamic and Structural Properties of Metals and Alloys
- Microbial Metabolites in Food Biotechnology
Universidade Federal do Amazonas
2016-2025
Total (France)
2024
Universidade Federal de Santa Catarina
2004-2011
A structural peculiarity of the electronic topological transition (ETT) occurring within pressure stability range low-pressure rhombohedral phase I has been evidenced in Bi${}_{2}$Te${}_{3}$. On both sides ETT structure remains unchanged. Nevertheless, precise investigation x-ray diffraction patterns allows us to conclude that this obeys lamellar character compound but a counterintuitive way. Indeed, signature can be detected only layers' plane variation lattice parameter $a$ with 25%...
Polypyrrole (PPY) powder was chemically synthesized using ferric chloride (FeCl 3 ) and characterized by X‐ray diffraction (XRD), Le Bail Method, Fourier Transform Infrared Spectrometry (FTIR), Scanning Electron Microscopy (SEM). XRD pattern showed a broad scattering of semicrystalline structure composed main peaks centered at 2 θ = 11.4°, 22.1°, 43.3°. Crystallinity percentage estimated the ratio between sums peak areas to area amorphous halo due phase that PPY has around 20 (1)%. FTIR...
The effect of pressure on nanostructured rhombohedral α-Sb2Te3 (phase I) was investigated using X-ray diffraction (XRD) and Raman spectroscopy (RS) up to 19.2 25.5 GPa, respectively. XRD patterns showed two new high phases (named II III). From a Rietveld refinement α-Sb2Te3, the unit cell volume as function obtained values were fitted Birch–Murnaghan equation state (BM-EOS). best fit for bulk modulus B0=36.1±0.9 GPa its derivative B0′=6.2±0.4 (not fixed). Using refined structural data...
Peach palm fruit mesocarp (Bactris gasipaes var. gasipaes) is already consumed in the Northern region of Brazil, after its cooking and known as a source starch carotenoids like all fruits it has low storage stability. This work characterized extracted from peach using with water terms physical chemical properties. The SEM micrographs show that presented bimodal distribution (size 3.9–10.4 µm), while smaller granules had smooth surface an oval or conical shape, larger were spherical holes...
The pressure-induced phase transitions in nanostructured SnSe were investigated using angle-dispersive X-ray diffraction a synchrotron source along with first-principles density functional theory (DFT) calculations. variation of the cell parameters enthalpy calculations for pressures up to 18 GPa have been considered. Both experimental and theoretical approaches demonstrate transition at around 4 GPa. Below 8.2 patterns fitted Rietveld method space group Pnma (No. 62). lattice atomic...
Abstract The functional properties of starch could be improved with structural tuning through a number processing techniques, intensely explored in the past few years by several industries such as food, pharmacology, paper and cosmetics. current work proposes model for determining crystallinity B‐type Starch based only on X‐ray diffraction (XRD) Rietveld refinement method (RM). A sample food grade potato (described Starch) was submitted to modifications using high energy ultrasound followed...
Este estudo teve como objetivo analisar a gestão escolar pode contribuir para formação de projetos vida dos estudantes, considerando as diversas esferas da educação formal e os desafios contemporâneos sociedade. Para atingir esse objetivo, pesquisa foi desenvolvida por meio uma abordagem qualitativa, com base em bibliográfica. A metodologia consistiu na revisão obras acadêmicas artigos relevantes que abordam vida, ênfase inter-relação entre esses temas. Os resultados indicaram exerce um...
The crystalline structures of the superionic high-temperature copper selenides Cu 2− x Se (0 < 0.25) produced using mechanical alloying were investigated X-ray diffraction (XRD). measured XRD patterns showed presence peaks corresponding to α-Cu 2 phase in as-milled sample, and its structural data determined by means a Rietveld refinement procedure. After heat treatment argon at 473 K for 90 h, this transforms 1.8 phase, whose also refinement. In very low occupation trigonal 32( f ) sites...
Nanocrystalline ZnTe was prepared by mechanical alloying. X-ray diffraction (XRD), energy dispersive spectroscopy, Raman and photoacoustic absorption spectroscopy techniques were used to study the structural, chemical, optical, thermal properties of as-milled powder. An annealing alloyed sample at 590 °C for 6 h done investigate optical in a defect-free (close bulk form). The main crystalline phase formed zinc-blende ZnTe, but residual trigonal tellurium hexagonal ZnO phases also observed...
Nanocrystalline Bi2Te3 was produced by mechanical alloying and its properties were investigated differential scanning calorimetry (DSC) x-ray diffraction (XRD), Raman spectroscopy (RS), photoacoustic (PAS). Combining the XRD RS results, volume fraction of interfacial component in as-milled annealed samples estimated. The PAS results suggest that contribution to thermal diffusivity nanostructured is very significant.
The pressure-induced phase transitions in SnSe have been investigated using the first-principles density functional calculations. experimental results nanostructured revealed a transition at 4 GPa whereas that well-crystallized samples showed 10 GPa. To understand above discrepancy, we used pseudohybrid Hubbard on fully-relaxed of SnSe. calculated electron energy gap 0.83 eV is good agreement with values 0.86 and 0.898 eV. analysis quasi-particle band structures, Fermi level, Fermi-surface...
Nanostructured Sb2Te3 was produced from Sb and Te by mechanical alloying for 3 h. Volume fractions of crystalline interfacial components the milled powder were estimated X-ray diffraction (XRD) pattern corrected polarization, re-absorption, inelastic scattering converted to electron units using theoretical value mean square factor 〈f2〉 Sb2Te3. Annealing showed that particles are stable up at least 583 K. The influence component on optical thermal properties as-milled annealed studied through...
Abstract The ball milling process was used to obtain nanocrystalline cubic silicon. Between 5 and 10 h of milling, amorphous silicon also formed. differential scanning calorimetry (DSC) spectrum a powder milled for showed that the amorphous–crystalline phase transition occurs at about 450 °C. According Raman spectroscopy X‐ray diffraction results, volume fractions crystalline, interfacial phases were 30, 39 31%, respectively. Copyright © 2010 John Wiley & Sons, Ltd.