A5058914488- ZnO doping and properties
- Magnetic Properties and Synthesis of Ferrites
- Advanced Condensed Matter Physics
- Transition Metal Oxide Nanomaterials
- Iron oxide chemistry and applications
- Microstructure and Mechanical Properties of Steels
- Copper-based nanomaterials and applications
- Magnetic and transport properties of perovskites and related materials
- Multiferroics and related materials
- Nuclear Materials and Properties
- Origins and Evolution of Life
- Nuclear materials and radiation effects
- Magnetic properties of thin films
- Magnetic Properties and Applications
- High Temperature Alloys and Creep
- Chemical Analysis and Environmental Impact
- Photosynthetic Processes and Mechanisms
- Cassava research and cyanide
- Fusion materials and technologies
- Electronic and Structural Properties of Oxides
- Isotope Analysis in Ecology
- Clay minerals and soil interactions
- Mine drainage and remediation techniques
- Magneto-Optical Properties and Applications
- Magnetic and Electromagnetic Effects
Universidade Estadual de Maringá
2014-2024
Universidade Federal de São Carlos
2024
Fe2O3 nanoparticles with sizes ranging from 15 to 53 nm were synthesized by a modified sol-gel method. Maghemite particles as well admixture of maghemite and hematite obtained characterized XRD, FTIR, UV-Vis photoacoustic Mössbauer spectroscopy, TEM, magnetic measurements. The size hematite/maghemite ratio the controlled changing Fe:PVA (poly (vinyl alcohol)) monomeric unit used in medium reaction (1:6, 1:12, 1:18, 1:24). average decreases, content increases increasing PVA amount until 1:18...
Fe 2 O 3 nanoparticles (as maghemite and hematite mixtures) were prepared using adapted sol-gel method from a polyvinylpyrrolidone (PVP) aqueous solution in various 3+ : PVP monomer ratios. Analysis of X-ray diffraction was obtained to evaluate the crystalline state, average crystallite size, composition iron oxide phases. The morphology size evaluated by electronic transmission microscopy. Magnetic properties analyzed at low room temperatures. Optical characteristics UV-Vis photoacoustic...
Glyphosate (N- (phosphonomethyl) glycine) is one of the most widely used herbicides in world. In literature, there are several studies describing interaction between glyphosate and clay minerals. However, a lack data this marine environments. research, we examined adsorption onto montmorillonite presence artificial seawater. Mössbauer showed that phosphonate group with Fe2+ prevents its oxidation to Fe3+. X-ray diffractograms takes place only surface not interlayers. Infrared spectroscopy...
Plates of solution annealed Maraging-350 steel were submitted to aging under an inert atmosphere, varying the time and temperature. The aged samples characterized by X-ray diffraction Mössbauer spectroscopy. results revealed that treatments induced reversion austenite, in amounts vary with temperature heat treatment. lattice parameters martensite austenite phases, as well their hyperfine parameters, obtained at all conditions. No intermetallic compounds identified any samples, but a poorly...
Abstract This study investigated the synthesis of goethite under conditions resembling those prebiotic Earth. The artificial seawater used contains all major elements as well amino acids (α-Ala, β-Ala, Gly, Cys, AIB) that could be found on spectroscopic methods (FT-IR, EPR, Raman), scanning electron microscopy (SEM) and X-ray diffraction showed in any condition Gly Cys favoured formation goethite, plus β-Ala distilled water AIB hematite for other a mixture were obtained. Thus general no...
Abstract In the present work, interactions between forsterite-91 with distilled water and artificial seawater were studied at two pHs (2.0 8.0) using different techniques. A large increase in pH was observed for samples incubated an initially acidic (2.0) due to dissolution of seawater. Thus, hydrothermal vents, amount hydrocarbons magnetite should be expected release Fe(II). The PZC decreased IEP increased when treated ions from had effect on zeta potential. Scanning electron microscopy...
Pyrochlore-related compounds of the ${R}_{2}{\text{FeTaO}}_{7}$ type (with $R=\text{Gd}$, Eu, Dy, and Y) were synthesized by solid-state reaction precursor oxides. The structurally magnetically characterized x-ray diffraction, M\"ossbauer spectroscopy, magnetic measurements. results revealed that this subfamily pyrochlores crystallizes with $\mathbf{R}\overline{\mathbf{3}}$ symmetry, where iron tantalum occupies two different crystallographic sites. Magnetic phase transition to a long-range...
Magnetite is an iron oxide mineral component of primitive Earth. It naturally synthesized in different ways, such as magma cooling well olivine decomposition under hydrothermal conditions. probable magnetite played a significant role biogenesis. The seawater used the current work contained high Mg2+, Ca2+ and SO42- concentrations, unlike today that has Na+ Cl- concentrations. likely this better resembled ion composition seas Earth from 4 billion years ago. Cyanide thiocyanate were common...
U-xZr-yNb alloys with values of x varying from 32% to 50% (wt.%Zr) and y 6% 10% (wt.%Nb) were produced by the arc melting technique. The effect addiction zirconium niobium on phase stabilization γ-U, lattice parameter, microstructure elemental composition examined X-ray diffraction (XRD), scanning electron microscopy (SEM) energy dispersive spectroscope (EDS) techniques. crystallized in a cubic symmetry composed γ-U(Zr,Nb) matrix β-Zr small precipitates, when content is up 55 wt.%. With...
Considered one of the most promising building blocks life on primitive Earth, cyanide and its complexes are likely to have played an important role in emergence planet. Investigation into Earth has primarily considered high concentrations, but concentration oceans prebiotic was exceptionally low. Thus, Bernal's hypothesis allowed investigators work around this problem. We observed, however, that does not adsorb onto several minerals; therefore, ferrocyanide could be used as a source when...