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Subject: search.filters.subject.Sodium niobate

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    Facile synthesis of lead-free piezoelectric sodium niobate (NaNbO 3) Powders via the solution combustion method
    (2011-07-29)
    Chaiyo, Nopsiri
    ;
    Ruangphanit, Anucha
    ;
    Boonchom, Banjong
    ;
    Vittayakorn, Naratip
    Nanocrystalline perovskite sodium niobate, NaNbO<inf>3</inf> (NN), was prepared by means of the glycine-nitrate combustion process (GNP). This was achieved by using sodium nitrate and niobium pentoxide as starting materials. The X-ray diffraction technique (XRD) was used to investigate the phase formation and purity of synthesized powder. The morphology of the powder obtained was characterized using a scanning electron microscope (SEM). The amount of glycine in the starting solution was found to have significant influence on the combustion process and the final phase purity. The fuel-rich ratio (fuel-to-oxidant molar ratio of 1.0) was found to produce NaNbO <inf>3</inf> powder of an average crystalline size (defined by XRD) of 31.31 ± 4.37 nm. Calcination at 400°C for 4 h produced single phase NN with an average crystalline size of about 26.60 to 37.14 nm. Copyright © Taylor &Francis Group, LLC.
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    Solution combustion synthesis and characterization of lead-free piezoelectric sodium niobate (NaNbO3) powders
    (2011-02-03)
    Chaiyo, Nopsiri
    ;
    Muanghlua, Rangson
    ;
    Niemcharoen, Surasak
    ;
    Boonchom, Banjong
    ;
    Vittayakorn, Naratip
    Nano-crystalline sodium niobate (NaNbO<inf>3</inf>) powder was synthesized by the solution combustion synthesis of sodium nitrate (NaNO<inf>3</inf>) and Nb<inf>2</inf>O<inf>5</inf> using glycine as the fuel. The chemical reaction, nucleation mechanisms and influence of the fuel-to-oxidizer ratio to phase formation were studied. The precursor and product powders were characterized, using thermo gravimetric analysis (TGA), differential thermal analysis (DTA), the X-ray diffraction technique (XRD), scanning electron microscope (SEM) and Fourier transform infrared (FTIR) spectroscopy. As-prepared powder possesses an orthorhombic crystal structure with an X-ray diffraction pattern that could be matched with the perovskite, NaNbO<inf>3</inf> JCPDS no. 82-0606. Perovskite NaNbO<inf>3</inf> phase, with a mean crystalline size (calculated by X-ray line broadening) ranging from 44.51 ± 11.99 nm (ratio of 0.7) to 26.11 ± 13.69 nm (ratio of 2.0) was obtained. The SEM image shows polyhedral-shaped powder with a mean particle size of 137 ± 52 nm and 226 ± 46 nm for as-prepared and calcined powder, respectively. © 2010 Elsevier B.V. All rights reserved.