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Author: search.filters.author.Vittayakorn, NaratipSubject: search.filters.subject.electrical properties

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    Effect of the Firing Temperatures on the Phase Evolution and Electrical Properties of 0.85[0.94Bi0.5Na0.5TiO3-0.06BaTiO3]-0.15[Na0.73Bi0.09NbO3] Ceramics Synthesized via the Solid-State Combustion Method
    (2023-01-01)
    Pattanakasem, Wiwat
    ;
    Yotthuan, Surirat
    ;
    Hongsamsibjed, Pakornkiat
    ;
    Suriwong, Tawat
    ;
    Prasertpalichat, Sasipohn
    In this research paper, we describe 0.85[0.94Bi<inf>0.5</inf>Na<inf>0.5</inf>TiO<inf>3</inf>-0.06BaTiO<inf>3</inf>]-0.15[Na<inf>0.73</inf>Bi<inf>0.09</inf>NbO<inf>3</inf>] (BNT-BT-NBN) ceramics fabricated by the solid-state combustion technique. The phase evolution, microstructure, dielectric, ferroelectric and energy storage properties were examined. The BNT-BT-NBN powders and ceramics were calcined and sintered between 650–900 °C and 1100–1175 °C, respectively, for 2 h. All samples showed a typical perovskite structure, as revealed by X-ray diffraction. The Rietveld refinement analysis of the ceramics suggested the samples sintered between 1100 and 1150 °C had coexisting R + T phases, while the R + T+C phases were observed in the ceramics sintered at 1175 °C. The average grain size of the samples increased from 0.52 to 1.39 μm with increased sintering temperature. The density of the ceramics increased from 5.12 to 5.45 g/cm<sup>3</sup> when the sintering temperature increased from 1100 to 1150 °C, and then decreased. Increasing the sintering temperature from 1100 to 1150 °C caused the dielectric constant at T <inf>s</inf> (ε <inf>s</inf>) and the dielectric constant at T <inf>m</inf> (ε <inf>m</inf>) to increase from 1727 to 1945 and 1564 to 1750, respectively, and then ε <inf>s</inf> and ε <inf>m</inf> declined. All BNT-BT-NBN ceramics had good dielectric temperature stability with only a±10% change when the temperature ranged from room temperature to ∼300 °C. The optimum energy-storage properties (W <inf>rec</inf> = 0.62 J/cm<sup>3</sup> and η = 83.2%) were obtained from the BNT-BT-NBN ceramics sintered at 1150 °C for 2 h. This data indicates that BNT-BT-NBN ceramics can be useful as lead-free materials for high density energy-storage capacitors.
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    Dielectric, ferroelectric and piezoelectric properties of the lead free 0.9BaTiO3-(0.1- x)Bi0.5Na0.5TiO3- x Bi(Mg0.5Ti0.5)O3 solid solution
    (2016-01-02)
    Mayamae, Jitkasem
    ;
    Sukkha, Usa
    ;
    Niemchareon, Surasak
    ;
    Muanghlua, Rangson
    ;
    Vittayakorn, Naratip
    Solid solution of 0.9BaTiO<inf>3</inf>-(0.1-x)Bi<inf>0.5</inf>Na<inf>0.5</inf>TiO<inf>3</inf>-xBi(Mg<inf>0.5</inf>Ti<inf>0.5</inf>)O<inf>3</inf> (BT-BNT-xBMT) system, where x = 0.00, 0.02, 0.04, 0.06, 0.08, 0.10, was synthesized by the solid state reaction. Dense BT-BNT-xBMT ceramics were obtained by sintering at 1,150-1,250C for 4 h. The effect of BMT on crystal structure and electrical property of BT-BNT ceramics was investigated as a function of composition, x, using X-ray diffraction, dielectric spectroscopy, hysteresis and strain measurements. The crystal structure of solid solution BT-BNT-xBMT, where x = 0.00-0.10, successively transforms from tetragonal to pseudocubic symmetry, with increased BMT concentration. Temperature dependence of dielectric constant (ε<inf>r</inf>) and dielectric loss (tanδ) for BT-BNT-xBMT at various frequencies showed that phase transition of ceramics changed from ferroelectric to relaxor-like behavior as BMT content increased. Furthermore, remanent polarization (P<inf>r</inf>), coercive field (E<inf>c</inf>) and the normalized strain (d<inf>33</inf>∗) of BT-BNT-xBMT ceramics tend to decrease with increasing BMT concentration.
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    The effect of firing temperatures on (Pb0.75Ba 0.25)(Zr0.70Ti0.30)O3 ceramics prepared via the combustion technique
    (2013-12-01)
    Sittiketkorn, Panadda
    ;
    Wongtey, Pongkiti
    ;
    Vittayakorn, Naratip
    ;
    Bongkarn, Theerachai
    The (Pb0.7<inf>5</inf>Ba0.2<inf>5</inf>)(Zr<inf>0.70</inf>Ti <inf>0.30</inf>)O<inf>3</inf> (PBZT) ceramics were prepared via the combustion technique. (CO(NH<inf>2</inf>)<inf>2</inf>) was used as a fuel. The effect of firing temperature on PBZT's phase formation, microstructure and electrical properties were investigated. The calcination and sintering temperatures were 600°C-1000°C and 1100°C-1300°C. The pure rhombohedral perovskite was obtained from the powders calcined at 850°C. The average particle size tended to increase with increased calcination temperatures. A pure rhombohedral perovskite phase was found in all pellet samples. The average grain size and linear shrinkage tended to increase from 0.57 to 2.15 μm and from 6.8 to 15.8% with increased sintering temperatures. The dielectric results indicated the relaxer behavior of PBZT ceramics. The Curie temperature tended to decrease with increasing sintering temperatures. The highest density (∼7.39 g/cm <sup>3</sup>) and highest dielectric constant (∼8620) were obtained by using the combustion technique which was higher than the conventional mixed oxide method. © 2013 Copyright Taylor and Francis Group, LLC.