Recent Submissions

  • High stability of properties in morphotropic phase boundary Bi0.5Na0.5TiO3-BaTiO3 piezoceramics 

    Machado, Rodrigo; Ochoa Guerrero, Diego A.; dos Santos, Valdeci B.; Cerdeiras Montero, Elena; Mestres Vila, Lourdes; García García, José Eduardo (2016-11-15)
    Article
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    The (1-x)Bi0.5Na0.5TiO3–xBaTiO3 (BNT-xBT) system with composition at its morphotropic phase boundary (MPB) has received significant attention because of their attractive properties as lead-free piezoceramics. Although the ...
  • Bifurcation analysis of a DC–DC bidirectional power converter operating with constant power loads 

    Cristiano, Rony; Pagano, Daniel J.; Benadero García-Morato, Luis; Ponce, Enrique (2016-04)
    Article
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    Direct current (DC) microgrids (MGs) are an emergent option to satisfy new demands for power quality and integration of renewable resources in electrical distribution systems. This work addresses the large-signal stability ...
  • Microstructure effects on BaTiO3/BaTi0.8Zr0.2O3 composites properties 

    Martins Amaral, Thiago; Antonelli, Eduardo; Ochoa Guerrero, Diego A.; García García, José Eduardo; Hernandes, Antonio Carlos (2016-05-15)
    Article
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    The dielectric, pyroelectric and ferroelectric properties of bilayered BaTiO3/BaTi0.8Zr0.2O3 ceramics are described and correlated with their microstructure. Different sintering times are employed to change the microstructure ...
  • Extrinsic response enhancement at the polymorphic phase boundary in piezoelectric materials 

    Ochoa Guerrero, Diego A.; Esteves, Giovanni; Jones, Jacob L.; Rubio-Marcos, Fernando; Fernández Lozano, José Francisco; García García, José Eduardo (2016-04-04)
    Article
    Open Access
    Polymorphic phase boundaries (PPBs) in piezoelectric materials have attracted significant interest in recent years, in particular because of the unique properties that can be found in their vicinity. However, to fully ...
  • Extensive domain wall contribution to strain in a (K,Na)NbO3-based lead-free piezoceramics quantified from high energy X-ray diffraction 

    Ochoa Guerrero, Diego A.; Esteves, Giovanni; Iamsasri, Thanakorn; Rubio-Marcos, Fernando; Fernández Lozano, José Francisco; García García, José Eduardo; Jones, Jacob L. (Elsevier, 2016-08)
    Article
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    The origins of high piezoelectric properties in the lead-free (K,Na)NbO3-based tetragonal composition (K0.44Na0.52Li0.04)(Nb0.86Ta0.10Sb0.04)O3 (KNL-NTS) is investigated by quantifying the intrinsic and extrinsic contributions ...
  • Preisach modeling of temperature-dependent ferroelectric response of piezoceramics at sub-switching regime 

    Ochoa Guerrero, Diego A.; García García, José Eduardo (2016-04)
    Article
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    The Preisach model is a classical method for describing nonlinear behavior in hysteretic systems. According to this model, a hysteretic system contains a collection of simple bistable units which are characterized by an ...
  • Nonlinear analysis of interconnected power converters: a case study 

    Benadero García-Morato, Luis; Cristiano, Rony; Pagano, Daniel J.; Ponce, Enrique (2015-09-01)
    Article
    Open Access
    In this paper the nonlinear dynamics of interconnected power converters in an islanded direct current (DC) microgrid is analyzed. By using a simplified scheme based on two cascaded converters we analyze the dynamical ...
  • Extrinsic contribution and instability properties in lead-based and lead-free piezoceramics 

    García García, José Eduardo (2015-11-01)
    Article
    Open Access
    Piezoceramic materials generally exhibit a notable instability of their functional properties when they work under real external conditions. This undesirable effect, known as nonlinear behavior, is mostly associated with ...
  • THz-conductivity of CVD graphene on different substrates 

    Gabriel Cortés, Daniel; Sempere, Bernat; Colominas, Carles; Ferrer Anglada, Núria (Wiley-VCH, 2015-10-23)
    Article
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    Optoelectronic properties of CVD graphene are charac-terized over a wide frequency range: THz, IR, visible and near-UV. We used Raman spectroscopy to characterize the synthesized graphene films. All graphene layers were ...
  • Growth and physical properties of highly oriented La-doped (K,Na)NbO3 ferroelectric thin films 

    Vendrell Villafruella, Xavier; Raymond, Oscar; Ochoa Guerrero, Diego A.; García García, José Eduardo; Mestres, Lourdes (2015-02-27)
    Article
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    Lead-free (K,Na)NbO3 (KNN) and La doped (K,Na)NbO3 (KNN-La) thin films are grown on SrTiO3 substrates using the chemical solution deposition method. The effect of adding different amounts of Na and K excess (0-20 mol%) is ...

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