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Enhanced electrical and energy storage performances of Fe, Sb co-doped BNBCTS ceramics synthesized via the solid-state combustion technique
(2024-12-01)
Kornphom, C.
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Saenkam, K.
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Yotthuan, S.
;
Vittayakorn, N.
;
Bongkarn, T.
In this study BNBCTS ceramics were co-doped with Fe and Sb to form (Bi<inf>0.5</inf>Na<inf>0.5</inf>)<inf>0.93</inf>(Ba<inf>0.945</inf>Ca<inf>0.055</inf>)<inf>0.07</inf>(Ti<inf>(0.9946-x)</inf>Sn<inf>0.0054</inf>)(Fe<inf>0.5</inf>Sb<inf>0.5</inf>)<inf>x</inf>O<inf>3</inf> ceramics (denoted as BNBCTS-xFS) with various x content and were prepared via the solid-state combustion technique to enhance the electrical and energy storage performance. The effect of co-doping Fe and Sb on the phase formation, defect dipole, microstructure, electrical and energy storage properties of BNBCTS-xFS ceramics was studied. When x content increased from 0.0 to 0.030, the amount of the rhombohedral (R) phase decreased from 51 to 24 % while the tetragonal (T) phase increased from 49 to 76 %. The increased Fe and Sb content increased the defect dipole of singly/doubly charged oxygen-vacancies (V<inf>O</inf>∙/ V<inf>O</inf>∙∙) and caused more Ti4+ to transition to Ti3+, which caused the transition temperature of the ferroelectric phase to relaxor state (T<inf>F-R</inf>) in the ceramics to drop to below room temperature and it exhibited relaxor characteristics at room temperature. The ceramic with an x content of 0.010 had the largest grain size (3.06 μm), excellence ferroelectric properties (P<inf>r</inf> ∼31.04 μC/cm2, P<inf>m</inf> ∼38.98 μC/cm2 and E<inf>c</inf> ∼18.28 kV/cm), the largest electro strain (∼0.175 %) and a large d<inf>33</inf>* of 350 pm/V. Moreover, when x = 0.020, the ergodic relaxor ceramic showed the smallest grain size (1.03 μm), the lowest remanant polarization (P<inf>r</inf>) of 4.52 μC/cm2 and the lowest coercive field (E<inf>c</inf>) of 8.37 kV/cm, at an electric field of 60 kV/cm. More importantly, energy storage properties at the electric breakdown strength (E<inf>b</inf> = 120 kV/cm) of the ceramics with an x content of 0.020 exhibited a recoverable energy storage density (W<inf>rec</inf>) of 1.81 J/cm3, a total energy storage density (W<inf>total</inf>) of 2.95 J/cm3 and an efficiency (η) of 61.30%, with excellent thermal (∼25–150 °C) and frequency stability (∼1–100 Hz). This study provides new insights into the modulation of BNBCTS ceramics with Fe and Sb co-doping, which could effectively improve the electrical properties and energy storage properties of BNBCTS-xFS ceramics.
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Microstructural, dielectric and optical properties of [KNbO 3 ] 0.9 - [BaNi 0.5 Nb 0.5 O 3 ] 0.1 perovskite ceramics
(2018-12-19)
Sriphan, S.
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Vittayakorn, N.
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Kiravittaya, S.
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Bongkarn, T.
In this work, [KNbO <inf>3</inf> ] <inf>0.9</inf> - [BaNi <inf>0.5</inf> Nb <inf>0.5</inf> O <inf>3</inf> ] <inf>0.1</inf> ( KBNNO) perovskite ceramics are synthesized under various conditions by using the solid-state combustion technique. Their microstructural, Raman, dielectric, optical, and photovoltaic properties are investigated. X-ray diffraction spectroscopy reveals that the synthesized ceramics have a cubic structure. A high purity KBNNO sample is obtained at the sintering temperature of 1100°C with the dwell time of 3 h. Raman spectroscopy of these ceramics shows a broadening of vibrational peaks for the sample sintered at 1130°C, which implies an existence of impurity phases. The dielectric constant of ∼3000 at room temperature is obtained. The optical absorption of light in visible range as well as the photovoltaic response are observed in this ceramic. This work demonstrates the potential usages of KBNNO in electrical and opto-electronic applications.
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Use of the combustion technique for the preparation of Ba(Ti 0.70Zr0.30)O3 ceramics
(2010-12-01)
Phungjitt, N.
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Panya, P.
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Vittayakorn, N.
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Bongkarn, T.
The preparation conditions for barium titanate zirconate [Ba(Ti <inf>0.70</inf>Zr<inf>0.30</inf>)O<inf>3</inf>] ceramics by the combustion method were studied. The X-ray diffraction pattern indicated that the calcined powders belonged to a cubic phase. The maximum percentage of the cubic perovskite phase was found in the sample calcined at 850°C. A pure cubic crystal structure was found in all ceramic samples. The average grain size increased with increasing sintering temperatures. The dielectric constant-temperature plots showed a maximum peak value of 5800 from ceramic sintered at 1350°C. The densities of samples corresponded to the dielectric constant. A diffuse phase transition was also observed.
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Effect of calcination temperatures on microstructure and phase formation of Ba(Zr0.25Ti0.75)O3 powders
(2008-12-01)
Bongkarn, T.
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Phungjitt, N.
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Vittayakorn, N.
In this work, the effect of calcination temperatures on the microstructure and phase formation of Ba(Zr<inf>0.25</inf>Ti<inf>0.75</inf>)O<inf>3</inf> (BZT) powders were investigated. The BZT powders were prepared via the solid state reaction method under various calcination temperatures. It was found that the second phases such as BaCO<inf>3</inf> ZrO<inf>2</inf>, BaZrO<inf>3</inf> and Ba<inf>2</inf>ZrO<inf>4</inf> existed in samples with calcination temperature below 1200 °C. Homogeneity and a highly pure perovskite phase of the BZT powders were obtained with calcination condition at 1300 °C for 4 h. Lattice parameter a and the percentage of cubic perovskite phase tended to increase with increasing calcination temperatures. The TG-DTA results corresponded to the XRD investigation. The microstructures of calcined powders exhibited an almost-spherical morphology and had a porous agglomerated form in all samples. The average particle sizes were increased from 0.2 to 1.1 μm when calcination temperatures were increased from 800 to 1350 °C. © 2008 Trans Tech Publications, Switzerland.

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