Listar QFA_Articles por autoría "6550d7f6-c97d-49e1-8596-3aff598e2de5"

Mostrando ítems 1-20 de 34

    • openAccess   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 ...

    • openAccess   A combined theoretical and experimental study of electronic structure and optical properties of β-ZnMoO4 microcrystals 

      Cavalcante, Laécio Santos; Moraes, E.; Almeida, M.A.P.; Dalmaschio, C.J.; Batista, N.C.; Varela, José A.; Longo, Elson; Siu Li, Maximo; Andres, Juan; Beltran, Armando Elsevier (2013)
      In this paper, a combined theoretical and experimental study on the electronic structure and photoluminescence (PL) properties of beta zinc molybdate ( -ZnMoO4) microcrystals synthesized by the hydrothermal method has ...

    • closedAccess   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 ...

    • closedAccess   A Theoretical Study on the Pressure-Induced Phase Transitions in the Inverse Spinel Structure Zn2SnO4 

      Gracia, Lourdes; Beltran, Armando; Andres, Juan ACS (2011-03)
      The structural and electronic properties of Zn2SnO4 under high pressure have been investigated using the density functional formalism under the nonlocal B3LYP approximation. We have determined its stability against ...

    • openAccess   Anomalous oriented attachment growth behavior on SnO2 nanocrystals 

      Stroppa, Daniel G.; Montoro, Luciano A.; Beltran, Armando; Conti, Tiago G.; Da Silva, Rafael O.; Andres, Juan; Leite, Edson R.; Ramírez, Antonio J. Royal Society of Chemistry (2011)
      This work reports a detailed characterization of an anomalous oriented attachment behaviour for SnO2 nanocrystals. Our results evidenced an anisotropic growth for two identical 〈110〉 directions, which are equivalent according ...

    • openAccess   Beta-Bi2O3 under compression: Optical and elastic properties and electron density topology analysis 

      Pereira, André L. J.; Gomis Hilario, Óscar; Sans, Juan A.; Contreras García, Julia; Manjón, F. J.; Rodríguez Hernández, P.; Muñoz, Alfonso; Beltran, Armando American Physical Society (2016-06)
      We report a joint experimental and theoretical study of the optical properties of tetragonal bismuth oxide (β−Bi2O3) at high pressure by means of optical absorption measurements combined with ab initio electronic band ...

    • closedAccess   CaSO4 and its pressure-induced phase transitions. A density functional theory study 

      Gracia, Lourdes; Beltran, Armando; Errandonea, Daniel; Andres, Juan American Chemical Society (2012-02)
      Theoretical investigations concerning possible calcium sulfate, CaSO4, high-pressure polymorphs have been carried out. Total-energy calculations and geometry optimizations have been performed by using density functional ...

    • openAccess   Characterization of the TiSiO4 structure and its pressure-induced phase transformations: density functional theory study 

      Gracia, Lourdes; Beltran, Armando; Errandonea, Daniel American Physical Society (2009)
      Theoretical investigations concerning the possible titanium silicate polymorphs have been performed using density functional theory at B3LYP level. Total-energy calculations and geometry optimizations have been carried ...

    • closedAccess   Density Functional Theory Study on the Structural and Electronic Properties of Low Index Rutile Surfaces for TiO2/SnO2/TiO2 and SnO2/TiO2/SnO2 Composite Systems 

      Beltran, Armando; Andres, Juan; Sambrano, Julio; Longo, Elson American Chemical Society (2008-08)
      The present study is concerned with the structural and electronic properties of the TiO2/SnO2/TiO2 and SnO2/TiO2/SnO2 composite systems. Periodic quantum mechanical method with density functional theory at the B3LYP level ...

    • closedAccess   Dopant segregation analysis on Sb:SnO2 nanocrystals 

      Beltran, Armando; Stroppa, Daniel G.; Montoro, Luciano A.; Conti, Tiago G.; Da Silva, Rafael O.; Andres, Juan; Leite, Edson R.; Ramírez, Antonio J. Wiley (2011-08-26)
      The development of reliable nanostructured devices is intrinsically dependent on the description and manipulation of materials properties at the atomic scale. Consequently, several technological advances are dependent on ...

    • openAccess   Effect of Pressure-Assisted Heat Treatment on Photoluminescence Emission of α-Bi2O3 Needles 

      Schmidt, Samara; Kubaski, Evaldo T.; Volanti, Diogo P.; Sequinel, Thiago; Bezzon, Vinicius Danilo N.; Beltran, Armando; Tebcherani, Sergio M.; Varela, José A. American Chemical Society (2015-10)
      Materials with high photoluminescence (PL) intensity can potentially be used in optical and electronic devices. Although the PL properties of bismuth(III) oxide with a monoclinic crystal structure (α-Bi2O3) have been ...

    • openAccess   Electronic structure and magnetic properties of FeWO4 nanocrystals synthesized by the microwave-hydrothermal method 

      Cavalcante, Laécio Santos; Morilla-Santos, C.; Lisboa Filho, Paulo N.; Beltran, Armando; Andres, Juan; Gracia, Lourdes; Longo, Elson; Almeida, M.A.P. Elsevier (2012)
      This communication reports that FeWO4 nanocrystals were successfully synthesized by the microwave-hydrothermal method at 443 K for 1 h. The structure and shape of these nanocrystals were characterized by X-ray diffraction, ...

    • openAccess   Enhancement of optical absorption by modulation of the oxygen flow of TiO2 films deposited by reactive sputtering 

      Beltran, Armando; Pereira, André L. J.; Lisboa Filho, Paulo N.; Acuña, Javier; Brandt, Iuri S.; Pasa, André A. American Institute of Physics (AIP) (2012)
      Oxygen-deficient TiO2 films with enhanced visible and near-infrared optical absorption have been deposited by reactive sputtering using a planar diode radio frequency magnetron configuration. It is observed that the increase ...

    • openAccess   Experimental and theoretical investigation of ThGeO4 at high pressure 

      Errandonea, Daniel; Kumar, Rhavi S.; Gracia, Lourdes; Beltran, Armando; Achary, S. N.; Tyagi, Alchilesh. K. American Physical Society (2009)
      We report here the combined results of angle-dispersive x-ray diffraction experiments performed on ThGeO4 up to 40 GPa and total-energy density-functional theory calculations. Zircon-type ThGeO4 is found to undergo a ...

    • openAccess   Experimental and Theoretical Study of Bi2O2Se Under Compression 

      Pereira, André L. J.; Santamaría Pérez, D.; Ruiz-Fuertes, J.; Manjón, F. J.; Cuenca-Gotor, V. P.; Vilaplana, Rosario; Gomis Hilario, Óscar; Popescu, Catalin; Muñoz, Alfonso; Rodríguez Hernández, P.; Segura García del Río, Alfredo; Gracia, Lourdes; Beltran, Armando; Ruleova, P.; Drasar, C.; Sans, Juan A. American Chemical Society (2018-04)
      We report a joint experimental and theoretical study of the structural, vibrational, elastic, optical, and electronic properties of the layered high-mobility semiconductor Bi2O2Se at high pressure. A good agreement between ...

    • openAccess   Experimental and theoretical study of SbPO4 under compression 

      De Jesus Pereira, André Luis; Santamaría Pérez, D.; Vilaplana, Rosario; Errandonea, Daniel; Popescu, Catalin; da Silva, Estelina Lora; Sans Tresserras, Juan Angel; Rodríguez-Carvajal, Juan; Muñoz, Alfonso; Rodríguez-Hernandez, Plácida; Mujica, Andres; Radescu, Silvana; Beltran, Armando; Otero de la Roza, Alberto; Nalin, Marcelo; Mollar, Miguel; Manjón, F. J. American Chemical Society (2019-12-26)
      SbPO4 is a complex monoclinic layered material characterized by a strong activity of the nonbonding lone electron pair (LEP) of Sb. The strong cation LEP leads to the formation of layers piled up along the a axis and linked ...

    • closedAccess   First-Principles Study of Pressure-Induced Phase Transitions and Electronic Properties of Ag2MoO4 

      Beltran, Armando; Gracia, Lourdes; Longo, Elson; Andres, Juan American Chemical Society (2014-01)
      We have performed a systematic first-principles investigation by using the density functional formalism with the nonlocal B3LYP approximation to calculate structural and electronic properties as well as phase transitions ...

    • closedAccess   First-Principles Study on Polymorphs of AgVO3: Assessing to Structural Stabilities and Pressure-Induced Transitions 

      Beltran, Armando; Gracia, Lourdes; Andres, Juan; Longo, Elson American Chemical Society (2017-11)
      In this paper, we present a comprehensive theoretical study, based on density-functional theory calculations, and which focuses on the structural and electronic properties of silver vanadium oxide (AgVO3) in the monoclinic ...

    • openAccess   High-pressure study of the behavior of mineral barite by x-ray diffraction 

      Santamaría Pérez, D.; Gracia, Lourdes; Garbarino, G.; Beltran, Armando; Chulia-Jordan, Raquel; Gomis Hilario, Óscar; Errandonea, Daniel; Ferrer Roca, Chantal María; Martínez García, Domingo; Segura García del Río, Alfredo American Physical Society (2011-08-02)
      In this paper, we report the angle-dispersive x-ray diffraction data of barite, BaSO4 , measured in a diamond-anvil cell up to a pressure of 48 GPa, using three different fluid pressure-transmitting media (methanol-ethanol ...

    • closedAccess   Insight into the Effects of Fe Addition on the Local Structure and Electronic Properties of SrTiO3 

      Da Silva, Luis F.; M’Peko, Jean Claude; Andres, Juan; Beltran, Armando; Gracia, Lourdes; Bernardi, Maria Inês B.; Mesquita, Alexandre; Antonelli, Eduardo; Moreira, Mario Lucio; Mastelaro, Valmor Roberto American Chemical Society (2014-01)
      This paper reports an experimental and theoretical investigation of the effects of adding Fe to the perovskite strontium titanate SrTiO3. The effects include changes in the short-order range structure as well as in the ...