Publications (428) View all
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Article: Direct in situ observation of the electron-driven synthesis of Ag filaments on α-Ag2WO4 crystals.
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ABSTRACT: 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 employed several techniques to characterise the material in depth. By using these techniques combined with first-principles modelling based on density functional theory, a mechanism for the Ag filament formation followed by a subsequent growth process from the nano- to micro-scale was proposed. In general, we have shown that an accelerated electron beam from an electronic microscope under high vacuum enables in situ visualisation of Ag filaments with subnanometer resolution and offers great potential for addressing many fundamental issues in materials science, chemistry, physics and other fields of science.Scientific Reports 04/2013; 3:1676. -
Article: Mechanochemical synthesis of yttrium manganite
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ABSTRACT: Export Date: 3 May 2013, Source: ScopusJournal of Alloys and Compounds 01/2013; 552:451-456. · 2.29 Impact Factor -
Article: A combined theoretical and experimental study of electronic structure and optical properties of β-ZnMoO4 microcrystals
Polyhedron 01/2013; 54:13 - 25. · 2.06 Impact Factor -
Article: High-voltage electrophoretic deposition of preferentially oriented films from multiferroic YMn2O5 nanopowders
Ceramics International. 01/2013; 39(2):2065-2068. -
Article: The influence of area/volume ratio on microstructure and non-Ohmic properties of SnO2-based varistor ceramic blocks
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ABSTRACT: This work deals with the electrical properties of SnO2-based varistor systems with different area–volume (A/V) ratio of the green compact. The influence of A/V ratio specially on microstructural homogeneity and different diameter-thickness (D/t) ratio of sintered compact mainly as a requisite to the existence of non-Ohmic properties is evaluated. The results evidence that, contrary of what is generally observed for ZnO-based varistor system, in the SnO2-based system, the A/V ratio of the green compacts does not influence the non-Ohmic properties, i.e. the homogeneity of the microstructure and the composition after sintering is conserved independently of the A/V ratio employed in the green compacts. Such independence was specifically observed by performing non-Ohmic measurement after cutting the sintered blocks in different slices and observing that the current–voltage curve of the slices are very similar for different A/V ratio of the green compacts before sintering. The observed behavior has its origin on the fact that A/V ratio does not affect the microstructure development during sintering due to the minimal CoO losses by vaporization for SnO2-based system, i.e. the stability of the dopant oxides is high when compared with that used in commercial ZnO·Bi2O3-based varistors in which, for instance, Bi2O3 volatilizes critically. On the other hand, it was found a critical value of A/V=5.0cm−1 for the ceramic blocks to effectively served as varistor, below this ratio the ceramics were highly resistive because of a high number of effective barriers ∼85% which is higher than normally found for ZnO-based systems (35%).Journal of Materials Science Materials in Electronics 04/2012; 20(1):49-54. · 1.08 Impact Factor
