Germanate
Mostrando 1-10 de 10 artigos, teses e dissertações.
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1. Ca2Ge7O16 nanowires grown from CaO and GeO2
Single crystalline Ca2Ge7O16 nanowires have been synthesized using CaO and GeO2 as the raw materials. Various factors that affect the formation and size of the Ca2Ge7O16 nanowires have been analyzed. The obtained products are characterized by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. The results show that the calci
Materials Research. Publicado em: 29/11/2011
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2. Vidros de germanato com nanopartículas metálicas e semicondutoras dopados com terras-raras para aplicações em fotônica. / Germanate glasses containing metalic an semiconductor nanoparticles dopes with rare-earth ions for photonic aplicattions.
This work presents a spectroscopic study about Eu3+, Nd3+ and Er3+ rare-earth doped germanate glasses containing metallic and semiconductor nanoparticles (NPs) aiming the development of new materials for photonic applications. These glasses have a large transmission window (400-4500 nm), high refractive index (~ 1.9), low phonon energy (700 cm-1), high mecha
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 01/09/2010
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3. Propriedades térmicas, estruturais e ópticas de vidros germanatos de bismuto e sua cristalização abaixo da temperatura de transição vítrea / Thermal, structural and optical properties of bismuth germanate glasses and their crystallization below the glass transition temperature
Materiais vítreos com propriedades similares às do cristal germanato de bismuto de composição Bi4Ge3O12, material cintilador que possui estrutura do tipo eulitita, são de interesse devido as suas propriedades luminescentes, que os tornam promissores para aplicação como dispositivos ópticos. Vidros do sistema GeO2-Bi2O3 (BGO) também tem sido tema de
Publicado em: 2010
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4. Fabrication and characterization of tellurite and germanate waveguides for optoelectronics applications. / Produção e caracterização de guias de onda de telureto e germanato para aplicações em optoeletrônica.
The objective of this work is the production and characterization of GeO2-PbO and TeO2-ZnO waveguides. The waveguides were produced using thin films and glasses by means of different procedures. The films were produced using the RF magnetron sputtering method and characterized by a variety of techniques. In particular, scanning electron microscopy was essent
Publicado em: 2010
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5. Desenvolvimento de técnica para nucleação de nanopartículas metálicas em vidros de germanato dopados com íons de túlio para aplicações em dispositivos fotônicos. / Development of metalic nanoparticles nucleation technique in thulium doped germanate glasses for applications in photonic devices.
Neste trabalho são apresentadas a preparação, a metodologia adotada para a nucleação de nanopartículas (NPs) de prata e a investigação das propriedades luminescentes do sistema vítreo GeO2-PbO dopado com íons de túlio e codopado com íons de túlio e itérbio, na presença de NPs de prata, visando aplicação em dispositivos fotônicos. Este siste
Publicado em: 2010
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6. CRYSTALLINE FLUORIDE FIBER LASER AND CHARACTERIZATION OF RARE EARTH DOPED FIBERS / Laser de fibra monocristalina de fluoretos e caracterização de fibras dopadas com terras raras
Diode pumped solid state lasers have supplied a large part of the search for high power lasers, with good beam quality, in addition, these lasers are useful for generation of visible laser radiation. Fiber lasers have the capacity to reach these high powers with a good beam quality, due to its special design which confines the radiation through long fiber le
Publicado em: 2008
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7. Produção e caraterização de materiais vítreos de germanato com nanopartículas metálicas e íons de érbio para aplicações em fotônica. / Production and characterization of germanate glasses with metallic nanoparticles and erbium ions for photonic applications.
This work presents the preparation and investigation of the luminescent properties of PbO-GeO2 and PbO-GeO2-Ga2O3 vitreous systems, doped with Erbium ions and containing silver, gold and copper metallic nanoparticles (NPs), for applications in photonic devices. These glasses have a large transmission window (400-4500nm), high refractive index (~1,9) and low
Publicado em: 2007
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8. Characterization of Bi4Ge3O12 single crystal by impedance spectroscopy
Bi4Ge3O12 (bismuth germanate - BGO) single crystals were produced by the Czochralski technique and their electrical and dielectric properties were investigated by impedance spectroscopy. The isothermal ac measurements were performed for temperatures from room temperature up to 750 °C, but only the data taken above 500 °C presented a complete semicircle in
Materials Research. Publicado em: 2003-12
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9. Detecção piezelétrica não-gravimétrica de boro empregando cristal de quartzo com eletrodo separado e superfície quimicamente modificada / Non-gravimetric piezoelectric detection of boron by using quartz crystal with electrode separated and chemically modified surface
Piezoelectric quartz crystals (PQCs) with electrode-separated configuration and chemically modified surface were used to develop a boron sensor. A detection cell was built in such a way that a stainless-steel electrode was held at a short distance (0.3 mm) from the PQC surface, whose original gold electrode was removed. By using impedance spectroscopy, oscil
Publicado em: 2003
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10. Germanium Does Not Substitute for Boron in Cross-Linking of Rhamnogalacturonan II in Pumpkin Cell Walls1
Boron (B)-deficient pumpkin (Cucurbita moschata Duchesne) plants exhibit reduced growth, and their tissues are brittle. The leaf cell walls of these plants contain less than one-half the amount of borate cross-linked rhamnogalacturonan II (RG-II) dimer than normal plants. Supplying germanium (Ge), which has been reported to substitute for B, to B-deficient p
American Society of Plant Biologists.