A5038685528- ZnO doping and properties
- Magnetic and transport properties of perovskites and related materials
- Copper-based nanomaterials and applications
- Quantum and electron transport phenomena
- Magnetic properties of thin films
- Semiconductor Quantum Structures and Devices
- Advanced Condensed Matter Physics
- Electronic and Structural Properties of Oxides
- Gas Sensing Nanomaterials and Sensors
- Magnetic Properties and Applications
- Catalytic Processes in Materials Science
- Magnetic Field Sensors Techniques
- Ferroelectric and Piezoelectric Materials
- Physics of Superconductivity and Magnetism
- Surface and Thin Film Phenomena
- Multiferroics and related materials
- Catalysis and Hydrodesulfurization Studies
- TiO2 Photocatalysis and Solar Cells
- Semiconductor materials and interfaces
- Magneto-Optical Properties and Applications
- Advanced Photocatalysis Techniques
- Information Science and Libraries
- Transition Metal Oxide Nanomaterials
- Power Line Communications and Noise
- Dielectric properties of ceramics
Universidade Federal de Alfenas
2013-2023
Instituto de Investigaciones en Ciencias de la Salud
2017-2018
Universitario Francisco de Asís
2017-2018
Paul Drude Institute for Solid State Electronics
2009-2010
Universidade Estadual de Campinas (UNICAMP)
2000-2008
National Institute of Telecommunications
2006-2007
Ceria (CeO2) plays a vital role in emerging technologies for environmental and energy-related applications. The catalytic efficiency of ceria nanoparticles depends on its morphology. In this study, CeO2 were synthesized by microwave-assisted hydrothermal method under different synthesis temperatures. samples characterized X-ray diffraction, transmission electron microscopy, Raman scattering spectroscopy, paramagnetic resonance spectroscopy the Brunauer–Emmett–Teller method. diffraction...
Ceria (CeO2) is a promising dilute magnetic semiconductor. Several studies report that the intrinsic and extrinsic structural defects are responsible for room temperature ferromagnetism in undoped transition metal doped CeO2 nanostructures; however, nature of kind defect necessary to promote stabilize such system still matter debate. In work presented here, nanorods from Ce1-xCuxO2-δ with x = 0, 0.01, 0.03, 0.05 0.10, more stable {111} surface exposed were synthesized by microwave-assisted...
Bulk Zn1−xCoxO samples were synthesized via standard solid-state reaction route with different Co molar concentrations up to 21%. A detailed microstructural analysis was carried out investigate alternative sources of ferromagnetism, such as secondary phases and nanocrystals embedded in the bulk material. Conjugating techniques we confirmed Zn replacement by ions wurtzite ZnO structure, which retains, however, a high crystalline quality. No segregated neither Co-rich detected. Superconducting...
We demonstrate the feasibility to prepare Co-doped ZnO thin films (Zn<sub>1−x</sub>Co<italic>x</italic>O, <italic>x</italic> = 0; 0.01; 0.03 and 0.05) <italic>via</italic> dip-coating technique, a very simple low-cost process. focus structural optical analyses in context of DMOs.
Nanostructured Co-doped anatase TiO2 (Ti1–xCoxO2−δ) samples were prepared and studied with particular emphasis on their compositional, structural, magnetic properties. A detailed microstructural analysis was carried out to investigate the nature of Co incorporation into matrix. By combining different techniques, we confirmed replacement Ti4+ by Co2+ ions in structure. Neither segregated secondary phases nor Co-rich nanocrystals detected. doping found introduce oxygen vacancies system means a...
In this report we present a systematic structural and magnetic analysis of Co-doped ZnO nanoparticles prepared via microwave-assisted hydrothermal route. The data confirm the incorporation Co ions into wurtzite lattice concentration mainly near/at surface nanoparticles. This spatial distribution is set to passivate nanoparticles, inhibiting nanoparticle growth suppressing observation ferromagnetic phase. Based on experimental theoretical results propose kinetic-thermodynamic model for...
We report electric-field-induced modulation of the spin splitting during charging and discharging processes a $p$-type $\mathrm{GaAs}∕\mathrm{AlAs}$ double-barrier resonant-tunneling diode under an applied bias magnetic field. In addition to conventional Zeeman effect, we find experimental evidence excitonic produced by combination Rashba spin-orbit interaction, Stark charge accumulation. The abrupt changes in photoluminescence with provide information about accumulation effects device.
We have investigated polarization-resolved photoluminescence under applied voltage in $p\text{\ensuremath{-}}i\text{\ensuremath{-}}p$ $\mathrm{Ga}\mathrm{As}∕\mathrm{Al}\mathrm{As}$ double-barrier diodes. observed oscillations the degree of polarization up to 36% at $B=15\phantom{\rule{0.3em}{0ex}}\mathrm{T}$ with sign reversals occurring near hole subband resonances. At high voltages a saturation 25% is observed. The data are interpreted by using simulations based on simple theoretical...
The authors investigate the circular polarization of electro- and photoluminescence emissions from quantum well contact layers a nonmagnetic GaAs–AlAs p-i-n resonant tunneling diode under an external magnetic field. emission evidences formation spin polarized two-dimensional electron gas at n-accumulation layer. electroluminescence presents strong σ− degree polarization, even for null Zeeman splitting energies, slight bias dependence. observed is mainly attributed to electrons injected into gas.
Thin Co films deposited onto p-type Si substrates show a marked transition on their transport properties for temperatures around 250 K. For higher than K, the planar conduction measured in our samples changes from electronic to hole-like and film resistance undergoes clear drop. The is also observed by change of magnetotransport studied films. This effect can be explained channel switching upper metallic hole inversion layer as we increase sample temperature. We that this may controlled...
A systematic study of magnetic and magnetotransport properties thin Co films on Si is reported in this work. The thicknesses 30, 160 440 Å were prepared by magnetron sputtering from a target onto Si(100) substrate held at room temperature. Resistance, magnetoresistance Hall effect measured the temperature range 5–350 K. Magnetization was same using SQUID magnetometer. Complete surface hysteresis loops 4 to 300 K means magneto-optical Kerr effect, order follow behavior coercivity easy axes...
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The transport of electrons through a GaAs/AlAs double-barrier structure with $p$-type doped contacts was investigated using time-resolved photoluminescence spectroscopy. Under illumination, the current-voltage characteristics device present two additional features attributed, respectively, to resonant $\ensuremath{\Gamma}\text{\ensuremath{-}}\ensuremath{\Gamma}$ and $\ensuremath{\Gamma}\text{\ensuremath{-}}X$ electron tunneling. Optical measurements for biases where these alternative...