Visualitza per autoria "a0ad0742-4049-4b53-b8c6-1a479542f1fa"
Ara mostrant els elements 1-18 d 18
-
A Combined Experimental and Theoretical Study on the Formation of Ag Filaments on β-Ag 2 MoO 4 Induced by Electron Irradiation
Andres, Juan; Ferrer, Mateus M.; Gracia, Lourdes; Beltran, Armando; Longo, V. M.; Cruvinel, Guilherme Henrique; Tranquilin, R. L.; Longo, Elson Wiley-VCH Verlag (2015)A combined experimental and theoretical study is presented to understand the novel observed nucleation and early evolution of Ag fi laments on β-Ag 2 MoO 4 crystals, driven by an accelerated electron beam from an electronic ... -
A Joint Experimental and Theoretical Study on the Nanomorphology of CaWO4 Crystals
Longo, V. M.; Gracia, Lourdes; Stroppa, Daniel G.; Cavalcante, Laécio Santos; Orlandi, Marcelo; Ramírez, Antonio J.; Leite, Edson R.; Andres, Juan; Beltran, Armando; Varela, José A.; Longo, Elson ACS (2011-08)By the joint use of experimental techniques such as field emission scanning electron microscopy (FEG-SEM), transmission electron microscopy (TEM), and high resolution transmission electron microscopy (HR-TEM) and ab initio ... -
A theoretical study on the photoluminescence of SrTiO<sub>3</sub>
Gracia, Lourdes; Andres, Juan; Longo, V. M.; Varela, José A.; Longo, Elson Elsevier (2010)This Letter deals with the assignment of photoluminescence (PL) emission spectra of SrTiO<sub>3</sub>. Ideal and distorted structures of SrTiO <sub>3</sub> model systems have been selected to localize and characterize at ... -
Direct in situ observation of the electron-driven synthesis of Ag filaments on a-Ag2WO4 crystals
Longo, Elson; Cavalcante, Laécio Santos; Volanti, Diogo P.; Gouveia, Amanda; Longo, V. M.; Varela, José A.; Orlandi, Marcelo; Andres, Juan Nature Publishing group (2013)In this letter, we report, for the first time, the real-time in situ nucleation and growth of Ag filaments on α-Ag2WO4 crystals driven by an accelerated electron beam from an electronic microscope under high vacuum. We ... -
Elucidating the real-time Ag nanoparticle growth on a-Ag2WO4 during electron beam irradiation: experimental evidence and theoretical insights
Da Silva Pereira, Wyllamanney; Andres, Juan; Gracia, Lourdes; San-Miguel, Miguel A.; da Silva, Edison; Longo, Elson; Longo, V. M. Royal Society of Chemistry (2015)Why and how Ag is formed when electron beam irradiation takes place on α-Ag2WO4 in a vacuum transmission electron microscopy chamber? To find an answer, the atomic-scale mechanisms underlying the formation and growth of ... -
Experimental and theoretical approach of nanocrystalline TiO2 with antifungal activity
Longo, V. M.; Picon, Francini C.; Zamperini, Camila; Albuquerque, Anderson R.; Sambrano, Julio; Vergani, Carlos; Machado Maciel, Ana Lúcia; Andres, Juan; Hernandes, Antônio C.; Varela, José A.; Longo, Elson Elsevier (2013-07-09)Using a solvothermal method for this research we synthesized nanocrystalline titanium dioxide (nc-TiO2) anatase particles with a mean diameter of 5.4 nm and evaluated their potential antifungal effect against planktonic ... -
Hierarchical Assembly of CaMoO4 Nano-Octahedrons and Their Photoluminescence Properties
Longo, V. M.; Cavalcante, Laécio Santos; Paris, Elaine Cristina; Sczancoski, Júlio César; Pizani, Paulo Sergio; Siu Li, Maximo; Andres, Juan; Longo, Elson; Varela, José A. ACS (2011-03)Hierarchical assemblies of CaMoO4 (CM) nano-octahedrons were obtained by microwave-assisted hydrothermal synthesis at 120 °C for different times. These structures were structurally, morphologically and optically characterized ... -
Photoluminescence in quasi-amorphous Pb0.8X0.2Zr0.53Ti0.47O3 (X = Ca, Sr and Ba) powders: An optical and structural study
Longo, V. M.; Silva, M. S.; De Figueiredo, A. T.; Franco, R. W. A.; Vila, Carles; Cilense, Mário; Varela, José A.; Longo, Elson; Andres, Juan Elsevier (2009)Crystalline and quasi-amorphous PZT and PZT:X (X = Ca, Sr and Ba) powders were obtained by the polymeric precursor method. Electron paramagnetic resonance (EPR) and photoluminescence (PL) data suggest that the presence of ... -
Photoluminescent behavior of SrZrO<sub>3</sub>/SrTiO<sub>3</sub> multilayer thin films
Moreira, Mario Lucio; Andres, Juan; Longo, V. M.; Li, Maximo Siu; Varela, José A.; Longo, Elson Elsevier (2009)A detailed investigation was made into the origin of photoluminescence in an alternate multilayer system of SrZrO<sub>3</sub> (SZO) and SrTiO<sub>3</sub> (STO) thin films. XRD and room-temperature PL studies revealed a ... -
Potentiated Electron Transference in a-Ag2WO4 Microcrystals with Ag Nanofilaments as Microbial Agent
Longo, V. M.; Foggi, Camila Cristina; Ferrer, Mateus M.; Gouveia, Amanda; André, Rafaela S.; Avansi, Waldir; Vergani, Carlos; Machado Maciel, Ana Lúcia; Andres, Juan; Cavalcante, Laécio Santos; Hernandes, Antônio C.; Longo, Elson American Chemical Society (2014-02)This study is a framework proposal for understanding the antimicrobacterial effect of both α-Ag2WO4 microcrystals (AWO) synthesized using a microwave hydrothermal (MH) method and α-Ag2WO4 microcrystals with Ag metallic ... -
Presence of excited electronic state in CaWO4 crystals provoked by a tetrahedral distortion: An experimental and theoretical investigation.
Beltran, Armando; Andres, Juan; Gracia, Lourdes; Longo, V. M.; Cavalcante, Laécio Santos; Avansi, Waldir; Li, Maximo Siu; Mastelaro, Valmor Roberto; Varela, José A.; Longo, Elson © American Institute of Physics (2011-08)By combining experimental techniques such as x-ray diffraction, Fourier transform Raman, ultraviolet-visible, x-ray absorption near edge structure, extended x-ray absorption fine structure spectroscopy, and theoretical ... -
Quantum Mechanics Insight into the Microwave Nucleation of SrTiO3 Nanospheres
Moreira, Mario Lucio; Longo, V. M.; Avansi, Waldir; Ferrer, Mateus M.; Andres, Juan; Mastelaro, Valmor Roberto; Varela, José A.; Longo, Elson American Chemical Society (2012)An extensive investigation of strontium titanate, SrTiO3 (STO), nanospheres synthesized via a microwave-assisted hydrothermal (MAH) method has been conducted to gain a better insight into thermodynamic, kinetic, and reaction ... -
Structural and electronic analysis of the atomic scale nucleation of Ag on α-Ag2WO4 induced by electron irradiation
Andres, Juan; Gracia, Lourdes; González Navarrete, Patricio; Longo, V. M.; Avansi, Waldir; Volanti, Diogo P.; Ferrer, Mateus M.; Lemos, Pablo S.; La Porta, Felipe A.; Hernandes, Antônio C.; Longo, Elson Nature Publishing Group (2014-06)In this work, we utilise a combination of theory, computation and experiments to understand the early events related to the nucleation of Ag filaments on α-Ag2WO4 crystals, which is driven by an accelerated electron beam ... -
Structural and optical properties of CaTiO3 perovskite-based materials obtained by microwave-assisted hydrothermal synthesis: An experimental and theoretical insight
Moreira, Mario Lucio; Paris, Elaine Cristina; Do Nascimento, G. S.; Longo, V. M.; Sambrano, Julio; Mastelaro, Valmor Roberto; Bernardi, Maria Inês B.; Andres, Juan; Varela, José A.; Longo, Elson Elsevier (2009)CaTiO3 powders were synthesized using both a polymeric precursor method (CTref) and a microwave-assisted hydrothermal (CTHTMW) method in order to compare the chemical and physical properties of the perovskite-based material ... -
Synthesis of wurtzite ZnS nanoparticles using the microwave assisted solvothermal method
La Porta, Felipe A.; Ferrer, Mateus M.; Santana, Yuri V.B. de; Raubach, Cristiane W.; Longo, V. M.; Sambrano, Julio; Longo, Elson; Andres, Juan; Li, Maximo Siu; Varela, José A. Elsevier (2013-04)In this article, we report the development of an efficient and rapid microwave assisted solvothermal (MAS) method to prepare wurtzite ZnS nanoparticles at 413 K using different precursors. The materials obtained were ... -
Toward an Understanding of Intermediate- and Short-Range Defects in ZnO Single Crystals. A Combined Experimental and Theoretical Study
Lima, R. C.; Macario, L .R.; Espinosa, J. W. M.; Longo, V. M.; Erlo, R.; Marana, N. L.; Sambrano, Julio; Dos Santos, M. L.; De Moura, Ana Paula; Pizani, Paulo Sergio; Andres, Juan; Longo, Elson; Varela, José A. American Chemical Society (2008-07)A joint use of experimental and theoretical techniques allows us to understand the key role of intermediate- and short-range defects in the structural and electronic properties of ZnO single crystals obtained by means of ... -
Toward an Understanding of the Growth of Ag Filaments on a-.Ag2WO4 and Their Photoluminescent Properties: A Combined Experimental and Theoretical Study
Longo, Elson; Volanti, Diogo P.; Longo, V. M.; Gracia, Lourdes; Nogueira, Içamira C.; Almeida, M.A.P.; Pinheiro, Antonio N.; Ferrer, Mateus M.; Cavalcante, Laécio Santos; Andres, Juan American Chemical Society (2013-12)A combined experimental and theoretical study was conducted on the structure and electronic properties of α-Ag2WO4 to clarify the nucleation and growth processes of Ag filaments on α-Ag2WO4 crystals induced by electron ... -
Toward an Understanding of the Growth of Ag Filaments on α-Ag2WO4 and Their Photoluminescent Properties: A Combined Experimental and Theoretical Study
Longo, Elson; Volanti, Diogo P.; Longo, V. M.; Gracia, Lourdes; Nogueira, Içamira C.; Almeida, M.A.P.; Pinheiro, Antonio N.; Ferrer, Mateus M.; Cavalcante, Laécio Santos; Andres, Juan American Chemical Society (2013)A combined experimental and theoretical study was conducted on the structure and electronic properties of α-Ag2WO4 to clarify the nucleation and growth processes of Ag filaments on α-Ag2WO4 crystals induced by electron ...