A5036983222- Luminescence Properties of Advanced Materials
- Glass properties and applications
- Quantum Dots Synthesis And Properties
- Solid State Laser Technologies
- Photorefractive and Nonlinear Optics
- Random lasers and scattering media
- Phase-change materials and chalcogenides
- Chalcogenide Semiconductor Thin Films
- Nuclear materials and radiation effects
- Porphyrin and Phthalocyanine Chemistry
- Advanced Chemical Sensor Technologies
- Pigment Synthesis and Properties
- Analytical Chemistry and Sensors
- Optical and Acousto-Optic Technologies
- Lanthanide and Transition Metal Complexes
- Crystal Structures and Properties
- Photonic Crystals and Applications
- Spectroscopy and Laser Applications
- Mineralogy and Gemology Studies
Universidade Federal do Triângulo Mineiro
2013-2019
Universidade Federal de Uberlândia
2006-2013
In this work, Eu3+-doped lead borosilicate glasses (SiO2–B2O3–PbO2) synthesized by fusion method had their optical properties investigated as a function of temperature. Atomic Force Microscopy images obtained for glass matrix annealed at 350 and 500 °C show precipitated crystalline phase with sizes 11 21 nm, respectively. Besides, the temperature increases from to 300 K strong Eu3+ photoluminescence (PL) enhancement takes place. This anomalous feature is attributed thermally activated...
Experimental evidence of spectroscopic parameter control was observed in Nd3+ ions embedded a SiO2–Na2O–Al2O3–B2O3 glass system. The parameters Ω2,4,6 and others were determined by the Judd–Ofelt theory. It found that these strongly dependent on concentration, indicating ligand field change. This Letter will present discuss possible mechanisms responsible for changes parameters. Furthermore, non-radiative energy transfer such as migration, cross relaxation losses from networked phonons OH−...
Experimental evidence has been observed for energy transfer from CdS nanocrystals, synthesized by the fusion method, to Nd(3+) ions embedded in vitreous substrates. These dot samples doped with neodymium have investigated combined optical absorption (OA), photoluminescence (PL), and time-resolved (PLRT) techniques. Radiative nonradiative transfers between ion levels, our knowledge not reported before, can be clearly PL spectra where emission band valleys correspond exactly peaks of doping...
We report rare evidence of energy transfer from CdSe quantum dots (QDs) to Nd3+ ions in a SNAB glass system using absorption electronic transitions ion as nonresonant excitation source. However, the luminescence band was observed at 880 nm (4F3/2→4I9/2 transition) under 409 only when were embedded with QDs. This happened because absorbed photons emitted by QDs excitation. Band overlap QD and optical bands caused photon produced valleys spectrum. contributed reduction lifetime 4F3/2 state.
The authors report clear evidence of radiative and nonradiative energy transfer from CdSe quantum dots to Nd3+ ions in a glass system synthesized by melting method. An efficient control can be obtained controlling the mean radius dots. Increase about 100% near infrared emission (4F3/2 → 4I9/2) was observed as function thermal annealing time.
This work reports on the thermal diffusivity of SiO2–Na2CO3–B2O3–Al2O3 (SNAB) glass system doped with semiconductor nanocrystals CdS and Nd3+ ions. Thermal (D) was obtained by Lens technique. It is shown that D decreases up to 30% when SNAB nanocrystals. The effect discussed in terms heat transport phonons as well interface surface scattering.
A set of sodium silicate glass matrices were synthesized to study the influence Na2O concentration on optical properties Eu3+. The samples characterized by absorption (OA), time and energy resolved photoluminescence Fourier Transform Infrared (FTIR). We observed that decreasing oxide affects OH radicals in host matrix. Adjusting obtained FTIR spectra Gaussian functions, we existence two possible non-radiative transfer channels with transition from 5D0 7F2 state Eu3+ ions. first was produced...
The energy-transfer process and the related migration mechanism of excitation energy, important in optical dynamics Nd-doped glasses, were investigated. In order to study transfer process, Nd3+-doped oxide glasses produced with doping concentration (N) ranging from 0.1to1.9wt% as Nd2O3. A microluminescence technique was used measure spatial distribution emitting light a function distance center laser-excitation spot different Nd3+-ion concentrations. Efficient long-range energy Nd3+ ions...
A set of sodium silicate glass matrices with different Na2O concentrations and doped constant Er3+ content were synthesized by fusion. The influence on the luminescence ions in region 1.53 μm was studied. Samples characterized optical absorption (OA), time energy resolved photoluminescence Fourier Transform Infrared (FTIR). Sodium oxide concentration controls OH radicals. FTIR showed a decrease radicals, which is correlated an increase lifetime transition at approximately μm. However,...
The processes of energy transfer and diffusion photons emitted by Nd3+ ions embedded into a glass sample were investigated. luminescence resolved in space allowed the observation photons' spatial distribution. In this paper, we propose fuzzy mathematical model that permits carrying out calculations based on neighborhood intensity excitation spot laser. This proposed differs from other well-known ones literature because it shows clearly profile surface.
Sintetizou-se, neste trabalho, duas séries de amostras composição (100 – X)B2O3 + (X)Na2O (mol %) com X = 10, 15, 20, 25 e 30, outra série similar dopada em 1 wt% Nd3+ o objetivo observar a influência estrutural do Na2O por meio dos parâmetros Judd-Ofelt. Utilizou-se técnicas ópticas aborção, fotoluminescência, polarização reflexão método Arquimedes para obter índice refração densidade volumétrica das matrizes respectivamente. Os espectros absorção óptica apresentaram bandas centradas torno...