A5032472426- Transition Metal Oxide Nanomaterials
- Physics of Superconductivity and Magnetism
- Gas Sensing Nanomaterials and Sensors
- Ion-surface interactions and analysis
- Silicon and Solar Cell Technologies
- ZnO doping and properties
- Copper-based nanomaterials and applications
- Magnetic properties of thin films
- Catalysis and Oxidation Reactions
- Theoretical and Computational Physics
- Advanced Condensed Matter Physics
- Semiconductor materials and interfaces
- Magnetic and transport properties of perovskites and related materials
- Silicon Nanostructures and Photoluminescence
- Electron and X-Ray Spectroscopy Techniques
- Electronic and Structural Properties of Oxides
- Conducting polymers and applications
- Integrated Circuits and Semiconductor Failure Analysis
- Polydiacetylene-based materials and applications
- Archaeological and Geological Studies
- Polyoxometalates: Synthesis and Applications
- Magnetic Bearings and Levitation Dynamics
- Electrodeposition and Electroless Coatings
- X-ray Spectroscopy and Fluorescence Analysis
- Advancements in Battery Materials
Universidade Federal de Pelotas
2011-2023
Universidade de São Paulo
2022
Universidade Federal da Paraíba
2016
Universidade Federal de Santa Catarina
2006-2009
Universidade Federal do Rio Grande do Sul
2001-2006
Pontifícia Universidade Católica do Rio Grande do Sul
2006
ZnO nanostructures were synthesized by a proteic sol-gel method, using zinc nitrate hexahydrate and gelatin as precursors. Size shape evolution of achieved annealing temperature in the range 250-1000 ºC. The crystalline structure, morphology optical properties nanoparticles characterized X-Ray Diffraction (XRD), Raman Spectroscopy (RS), Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM), Transmission (TEM), room Photoluminescence (PL). result structural characterization...
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...
We report on the synthesis and characterization of nanofibrous structures vanadium oxide by anodic electrodeposition. The electrodeposits are thick layers several micrometers consisting fibers with length in micrometer range a width about . At variance available reports, nanofibers were obtained without use templates or additives. Electrochemical was performed aqueous solutions containing observed spongelike structure, consequent large surface area, strong entanglement potentially important...
In this work an extensive characterization of Co doped Cu2O thin films grown by electrochemical deposition is presented. The showed ferromagnetic behavior, with impressive Curie temperature up to 700 K. Undoped samples also presented magnetic moments at room temperature, but much reduced when compared ones. observed magnetism in undoped and was taken as indicative a defect-mediated ferromagnetism. Moreover, the sample magnetization consequence decreasing defect density due thermal annealing....
In this work we have measured the electronic stopping powers of ${}^{4}\mathrm{He}$ and ${}^{7}\mathrm{Li}$ ions for channeling random directions in Si as a function incident ion energy. The $(〈100〉$ Li, $〈110〉$ $〈111〉$ Li He) (Li only) measurements cover wide energy range between 200 keV 9 MeV. Rutherford backscattering technique together with different multilayer targets has been employed present experiments. results are compared to calculations carried out framework unitary convolution...
Secondary ion mass spectroscopy, transmission electron microscopy, Rutherford backscattering/channeling spectrometry, and elastic recoil detection analysis measurements were used to determine the Cu gettering behavior induced by He implanted into Si samples. This study was done in an iterative way changing fluence (5×1015–3×1016 cm−2), implantation temperature (room or 350 °C), conditions (random channel implants). Upon postimplantation annealing at 800 °C for 600 s, addition projected range...
The electrodeposition of p-Cu2O layers on Co/p-Si planar structures for potential application as p/metal/p metal base transistors were investigated. deposits prepared from electrolytes containing lactic acid and copper sulphate characterized by Rutherford Backscattering Spectrometry (RBS), X - Ray Diffraction (XRD), Transmission Electron Microscopy (TEM). formation Cu2O/Co Schottky interfaces was confirmed electrical measurements.
Resumo Técnicas que envolvem a obtenção de argilas organofílicas vêm sendo estudadas por diversos pesquisadores, com o intuito otimizar processo e garantir um produto melhor qualidade. Todo estudo está embasado no fato dessas apresentarem uma vasta gama aplicações na engenharia. Porém, trabalhos enfatizam químico desses processos atualmente são pouco frequentes. Desta forma, principal objetivo deste trabalho foi estudar sorção tensoativos iônicos não em bentoníticas. No organofilização...
We report on ac magnetoresistance, R(T,H) and ZFC [MZFC(T)] FCC [MFCC(T)] dc magnetizations measurements of the a hole doped Y0.9Ca0.1Ba2Cu3O7-δ single crystal with propose to disclose correlation between zero resistance, TR0(H) magnetic irreversibility, Tirr(H) temperatures. The were performed PPMS measurement current density applied parallel sample ab plane. MZFC(T) MFCC(T) commercial SQUID magnetometer. For both H ≤ 50kOe c axis sample. contrasting data profile at H-T diagram shows that...
We have studied experimentally by electrical magnetoconductivity measurements the influence of site disorder, introduced chemical doping, on superconducting paring transition YBa2Cu3O7-δ superconductor. The were performed in and YBa1.9Sr0.1Cu3O7-δ single crystals with low magnetic fields applied either parallel or perpendicular to Cu-O atomic planes. in-plane conductivity results show systematic occurrence tree-dimensional Gaussian (3D), XY (3DXY) beyond fluctuation regimes, as temperature...
We report on systematic magnetization experiments in an Y1-xCaxBa2Cu3O7−δ (x = 0.25 at%) single crystal. The were made using a superconducting quantum interference device magnetometer (SQUID). Magnetic moments measured as functions of the temperature according to zero-field cooling (ZFC), field-cooled (FCC), and warming (FCW) prescriptions. time-dependence FC at fixed magnetic fields was studied. up 50 kOe applied paramagnetic response related state observed when strong enough parallel c...