Vittayakorn, Naratip

Preferred name

Alternative Name

Vittayakorn, N.

Vittayakorn, Narathip

Main Affiliation

School of Science

naratip.vi@kmitl.ac.th

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Electrical properties of bismuth potassium titanate-strontium titanate ferroelectric ceramics
(2010-07-30)
Phetnoi, Prapapim
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Niemcharoen, Surasak
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Muanghlua, Rangson
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Sutapun, Manoon
;
Vittayakorn, Naratip
In this paper, lead-free (Bi<inf>0.5</inf>K<inf>0.5</inf>)TiO<inf>3</inf> ceramics doped with SrTiO<inf>3</inf> was prepared by the conventional solid state reaction method with sintering temperature at 1040°C. The samples were characterized by X-ray diffraction analysis and Scanning Electron Microscopy. The dielectric, ferroelectric properties were also investigated. The results of X-ray diffraction reveal that SrTiO<inf>3</inf> diffuse into the Bi <inf>0.5</inf>K<inf>0.5</inf>TiO<inf>3</inf> lattices to form a solid solution with a pure perovskite structure. After the introduction of SrTiO<inf>3</inf> into Bi<inf>0.5</inf>K<inf>0.5</inf>TiO<inf>3</inf>, the dielectric constant at room temperature (ε<inf>r</inf>) was found to decrease with increasing SrTiO<inf>3</inf>. The broadness of the dielectric constant peak was observed with increasing SrTiO<inf>3</inf> content, especially that of the 0.94Bi <inf>0.5</inf>K<inf>0.5</inf>TiO<inf>3</inf> - 0.06 SrTiO<inf>3</inf> ceramic which exhibited a very broad curve over a wide temperature range. The Bi <inf>0.5</inf>K<inf>0.5</inf>TiO<inf>3</inf> - SrTiO<inf>3</inf> system was expected to be a new and promising candidate for lead-free capacitors.
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A rapid synthesis of cobalt cyclotetraphosphate Co2P 4O12 at low temperature
(2013-05-01)
Boonchom, Banjong
;
Vittayakorn, Naratip
The cobalt cyclotetraphosphate, Co<inf>2</inf>P<inf>4</inf>O<inf>12,</inf> was synthesized by evaporating a mixture of cobalt chloride hexahydrate, phosphoric acid and water at 70 °C, with further calcinations at 400 °C, 500 °C and 600 °C for 3 h. XRD results indicated that the Co <inf>2</inf>P<inf>4</inf>O<inf>12</inf> compounds obtained had only monoclinic phase with space group C<inf>2h</inf>6 (Z=4). From FT-IR spectra, vibrational modes corresponding to internal vibrations of the P <inf>4</inf>O<inf>12</inf>4- anion were identified. The morphologies and crystallite sizes for the Co<inf>2</inf>P<inf>4</inf>O<inf>12</inf> obtained from SEM data and X-ray line broadening showed non-uniform particles and 37-68 nm, respectively. All characterization methods showed that the monoclinic phase of Co<inf>2</inf>P<inf>4</inf>O<inf>12</inf> could be synthesized at the low temperature of 400 °C with short time consumption. The temperature was about 400 °C lower than that used in the previous synthesis method with CoCl <inf>2</inf> as reactant, and resulted in a cost-, energy-, and time-saving method. © 2012 Elsevier Ltd and Techna Group S.r.l.
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Performance and Behavior Analysis of Single-Electrode Triboelectric Nanogenerator for Energy Harvesting Floor Tiles
(2020-06-01)
Yingyong, Phonexai
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Thainiramit, Panu
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Vittayakorn, Naratip
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Isarakorn, Don
A triboelectric nanogenerator (TENG) is a promising candidate for harvesting the wasted energy from the ambient environment and utilizing it as an independent power source for batteries used in wearable and portable devices as well as sensing systems. This paper investigated the performance and behavior of triboelectric energy harvesters based on energy harvesting floor tiles by applying different mechanical input parameters such as contact gap, velocity, and vibration frequency to characterize the electrical characteristics while maintaining the applied pressure of 600 kPa and temperature. The results revealed that massive air gap displacement tends to generate higher electrical output. This demonstrated that the device could generate 2294.14 μW of optimal power and 95.50 μJ of total energy in 10 s at the mechanical excited frequency of 2 Hz with a fixed gap displacement of 5 mm. Moreover, the output power is proportional to the velocity of the cover plate movement. In contrast, varying the relative humidity (%RH) showed that the TENG could generate high electrical output at low relative humidity. The proposed work demonstrates that the TENG can function as an energy-harvesting device from low-frequency mechanical vibration for energy harvesting floor tiles.
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Synthesis, phase formation and characterization of Co4Nb 2O9 powders synthesized by solid-state reaction
(2008-12-01)
Chaiyo, N.
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Muanghlua, R.
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Ruangphanit, A.
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Vittayakorn, W. C.
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Vittayakorn, N.
A corundum-type structure of cobalt niobate (Co<inf>4</inf>Nb 2O<inf>9</inf>) has been synthesized by a solid-state reaction. The formation of the Co<inf>4</inf>Nb<inf>2</inf>O<inf>9</inf> phase in the calcined powders was investigated as a function of calcination conditions by differential thermal analysis (DTA) and X-ray diffraction (XRD) techniques. Morphology and particle size have been determined by scanning electron microscopy (SEM). It was found that the minor phases of unreacted Co <inf>3</inf>O<inf>4</inf> tend to form together with the columbite CoNb <inf>2</inf>O<inf>6</inf> phase at a low calcination temperature and short dwell time. It seems that the single-phase of Co<inf>4</inf>Nb<inf>2</inf>O <inf>9</inf> in a corundum phase can be obtained successfully at the calcination conditions of 900°C for 60 min, with heating/cooling rates of 20°C /min. © 2008 Trans Tech Publications, Switzerland.
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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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Phase transition and dielectric properties of lead free (K 0.5Na0.5)NbO3- Bi(Zn0.5Ti 0.5)O3 piezoelectric ceramics
(2009-12-01)
Sutapun, Manoon
;
Vittayakorn, Naratip
Lead-free piezoelectric ceramics of (1-x)(K0.5Na0.5) NbO3 - x(Bi(Zn0.5Ti0.5)O3; x = 0.00-0.30 were prepared via the two-stage mixed oxide fabrication technique. The crystal structure and ferroelectric phase transitions were studied by means of x-ray diffraction and thermal measurements. XRD results showed that a single-phase perovskite structurewas formed in the ceramics with x ≤ 0.25. For the ceramics with x = 0.30, a small amount of secondary phase Bi2Ti2O7 with a cubic structure was formed. The ceramics with a perovskite structure showed an orthorhombic phase at 0.00 ≤ x ≤ 0.010 and became rhombohedral at 0.010 < x ≤ 0.015 before transforming to a cubic phase at 0.015 < x ≤ 0.25. In addition, DSC results showed that the phase transition temperature of orthorhombic-tetragonal (TO-T) and tetragonal-cubic (TC) decreased when a small amount of BZT was added. The trend of enthalpy for orthorhombic → tetragonal phase transition and tetragonal → cubic phase were found to reduce with progressive increases in small amounts of BZT content. This behavior could originate from the more complex occupation of the A and B sites in an ABO3 perovskite structure. Copyright © Taylor & Francis Group, LLC.
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Study on thermal transformation of CuHPO4.H2O obtained by acetone-mediated synthesis at ambient temperature
(2012-11-01)
Baitahe, Rattanai
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Vittayakorn, Naratip
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Boonchom, Banjong
Copper hydrogenphosphate monohydrate, Cu- HPO<inf>4</inf>.H<inf>2</inf>O, was synthesized for the first time through simple and rapid method using the mixing of copper carbonate and phosphoric acid in acetone medium at ambient temperature. The obtained CuHPO<inf>4</inf>.H<inf>2</inf>O decomposed in three stages via dehydration and deprotonated hydrogenphosphate reactions, revealed by TG/DTG and DSC techniques. The kinetic triplet parameters (E<inf>a</inf>, A, and n) and thermodynamic functions (δHz.ast;, δGz.ast;, and δS*) for the first two decomposed steps were calculated from DSC data. All the obtained functions indicate that the deprotonated HPO<inf>4</inf> 2- reaction for the second step occurs at a higher energy pathway than the dehydration reaction for the first step. The calculated wavenumbers based on DSC peaks were comparable with FTIR results, which support the breaking bonds of OH (H<inf>2</inf>O) and P-OH (HPO<inf>4</inf> 2-) according to decomposed mechanisms. All the calculated results are consistent and in good agreement with Cu- HPO<inf>4</inf>.H<inf>2</inf>O's thermal transformation mechanisms. © Akademiai Kiado, Budapest, Hungary 2012.
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Sonochemical synthesis and characterization of copper oxide nanoparticles
(2011-01-01)
Wongpisutpaisan, Narongdet
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Charoonsuk, Piyanut
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Vittayakorn, Naratip
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Pecharapa, Wisanu
Copper oxide (CuO) nanoparticles were synthesized by a sonochemical process using copper nitrate and sodium hydroxide in the presence of polyvinyl alcohol (PVA) as a starting precursor. The precipitated product was calcined at various temperature ranging from 400-700°C. The physical microstructure and morphology of as-calcined nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). From XRD observation, it is evident that the high purity CuO nanoparticles were obtained by this synthesis process. It was additionally revealed that its crystallization and particle size was strongly dependent on the reaction time and calcination temperature. © 2011 Published by Elsevier Ltd.
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Magnetoelectric properties of BaTiO3 - Co0.5Ni0.5Fe2o4 composites prepared by the conventional mixed oxide method
(2013-10-29)
Pulphol, Nattakarn
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Muanglua, Rangson
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Niemcharoen, Surasak
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Pecharapa, Wisanu
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Vittayakorn, Wanwilai C.
Multiferroics, which display simultaneous ferrimagnetic and ferroelectric properties, have been interesting recently because of their potentially significant applications in multifunctional devices such as magnetic resonance, drug delivery, high-density data storage, ferrofluid technology, etc. Composites combining BaTiO<inf>3</inf> with Co<inf>0.5</inf>Ni<inf>0.5</inf>Fe<inf>2</inf>O<inf>4</inf> have influenced the interest of many researchers, due to their outstanding and distinguished character called magnetoelectric (ME). In this work, ferrimagnetic-ferroelectric composites of BaTiO<inf>3</inf> nanopowder and Co<inf>0.5</inf>Ni<inf>0.5</inf>Fe<inf>2</inf>O<inf>4</inf> nanopowders were prepared by a conventional mixed oxide method. The multiferroic ceramics were compounded with the formula, (1-x)BaTiO<inf>3-</inf>(x) Co<inf>0.5</inf>Ni<inf>0.5</inf>Fe<inf>2</inf>O<inf>4</inf>, in which x = 0, 0.05, 0.10, 0.20 and 0.35. All of the compositions were analyzed by an X-ray diffractometer (XRD) in order to reveal the phase of perovskite and spinal structure. Scanning electron microscopy (SEM) was used to examine the variation of morphology and grain size of the composited ceramics. The magnetism of all the ceramics was measured using a vibrating sample magnetometer (VSM). The results showed that microstructure and the amount of ferrite are related strongly with magnetization. © (2013) Trans Tech Publications, Switzerland.
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Application of chicken eggshell waste as a starting material for synthesizing calcium niobate (Ca4Nb2O9) powder
(2015-07-01)
Kamkum, Phonphan
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Atiwongsangthong, Narin
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Muanghlua, Rangson
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Vittayakorn, Naratip
This study focused on the possibility of using CaCO<inf>3</inf> from chicken eggshell waste as a starting material for synthesizing Ca<inf>4</inf>Nb<inf>2</inf>O<inf>9</inf> powder via a conventional solid state reaction. The heat behavior of CaCO<inf>3</inf> and Nb<inf>2</inf>O<inf>5</inf> raw material mixture was studied by thermogravimetric analysis (TGA). Phase formation of Ca<inf>4</inf>Nb<inf>2</inf>O<inf>9</inf> was studied as a function of calcination conditions by Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy and X-ray diffraction (XRD). The morphology and microstructure were charaterized via Scanning electron microscope (SEM). The X-ray fluorescence (XRF) results showed that the chicken eggshell contained more than 96.0% of CaCO<inf>3</inf> by weight. The XRD pattern peaks matched the peaks of calcite CaCO<inf>3</inf> ICDD No. 85-11108 very well. Furthermore, the XRD results and Rietveld refinement analysis confirmed that the purity and single phase of Ca<inf>4</inf>Nb<inf>2</inf>O<inf>9</inf> corresponded to the monoclinic structure (ICDD: 49-0911) obtained after the calcination process. The non-isothermal kinetic of Ca<inf>4</inf>Nb<inf>2</inf>O<inf>9</inf> also was investigated by the Ozawa methods. This study indicated that CaCO<inf>3</inf> from chicken eggshell waste is an alternative starting material for synthesizing Ca<inf>4</inf>Nb<inf>2</inf>O<inf>9</inf> powder.

Vittayakorn, Naratip

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