Vittayakorn, Naratip
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Preferred name
Vittayakorn, Naratip
Alternative Name
Vittayakorn, N.
Vittayakorn, Narathip
Main Affiliation
Email
naratip.vi@kmitl.ac.th
67 results
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Item type:Publication, Tailoring charge affinity, dielectric property, and band gap of bacterial cellulose paper by multifunctional Ti2NbO7 nanosheets for improving triboelectric nanogenerator performance(2023-02-01) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Electrical conductivity, magnetism, and optical properties of reduced BaCeO 3(2019-03-01); ; Kolodiazhnyi, TarasBaCeO <inf>3</inf> -based perovskites are well-known proton and oxygen ion conductors. For practical applications as electrolytes in solid oxide fuel cells, these compounds must be robust towards reduction of cerium ion. In this work, we explore the effect of reducing atmosphere on the physical properties of undoped and Nb-doped BaCeO <inf>3</inf> . The BaCeO <inf>3</inf> perovskite structure is thermodynamically stable at least up to 1450 <sup>∘</sup> C upon annealing in H <inf>2</inf> -containing atmosphere. Annealing at 1550 <sup>∘</sup> C causes a decomposition of the BaCeO <inf>3</inf> . The higher annealing temperature leads to higher concentration of Ce <sup>3 +</sup> ions and a higher electrical conductivity. With increasing the annealing temperature from 1300 to 1450 <sup>∘</sup> C , the activation energy of conductivity decreases from E <inf>a</inf> = 0.31–0.263 eV. We attribute the electrical conductivity in reduced BaCeO <inf>3</inf> to the activation of the small polaron hopping in agreement with the recent first-principles calculations. However, in contrast to the theoretical predictions, we find no evidence of the Ce <sup>3 +</sup> –Ce <sup>3 +</sup> spin-singlet small bipolarons. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Electrical and dielectric properties of barium titanate–polydimethylsiloxane nanocomposite with 0-3 connectivity modified with carbon nanotube (CNT)(2019-01-02); This study explored the preparation and electrical properties of 0–3 barium titanate/polydimethylsiloxane nanocomposites by dispersing barium titanate nanoparticles (BaTiO<inf>3</inf>; BT) into the polydimethylsiloxane (PDMS) matrix phase. The effect of barium titanate nanoparticles on electrical properties has been investigated systematically, and the relative permittivity of nanocomposites was found to increase significantly with increasing barium titanate content. Different theoretical models were used to predict the dielectric constant of these composites and compare their experimental value with the theoretical value in order to find an appropriate equation. The result indicated that the dielectric properties of composites are influenced not only by relative permittivity of the components but also dependence on interactions between ceramics and polymers. Furthermore, the preparation and dielectric properties of BT/PDMS nanocomposites modified with carbon nanotube (CNT) were also studied. The dielectric results demonstrate that adding CNT can enhance the relative permittivity of the BT/PDMS composite via improvement of dispersion and distribution of the BT nanoparticles in the PDMS matrix phase. Moreover, the electrical outputs from the BT/PDMS/CNT nanocomposites generator were measured under periodic knocking. The nanocomposites innovatively expand the feasibility of self-powered energy systems for smart sensor and energy harvesting applications. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Utilization of eggshell as a low-cost precursor for synthesizing calcium niobate ceramic(2018-07-18); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Magnetoelectric properties of BaTiO3 - Co0.5Ni0.5Fe2o4 composites prepared by the conventional mixed oxide method(2013-10-29); 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. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, AC Conductivity and dielectric properties of lepidocrocite-type alkali titanate tunable by interlayer cation and intralayer metal(2020-11-02); The lepidocrocite-type layered alkali titanate AxMyTi2-yO4 has diverse chemical compositions with variation in charge per formula unit x, the interlayer cation A+, and the intralayer metal M. Despite this multivariable nature, the composition dependence of physical properties is not well explored. We report herein the AC conductivity and the complementary dielectric properties of Cs0.7M0.35Ti1.65O4, K0.8M0.4Ti1.6O4 (M = Zn, Ni), and the mixed-interlayer ion Cs0.6K0.1Zn0.35Ti1.65O4. For Cs0.7Zn0.35Ti1.65O4, the total AC conductivity is ~7 × 10-8 to 2 × 10-6 S·cm-1 at 200-350 °C, associating with an activation energy Ea ∼865 meV. Meanwhile, the conductivity of K0.8Zn0.4Ti1.6O4 is higher by 1 order of magnitude at much lower temperature (25-150 °C) and a smaller Ea ∼250 meV. This difference originates from the compositional robustness of the cesium-containing samples, contrasting with the sintering-induced changes in the potassium analogues. For the latter, the loss of the interlayer K+ ion results in (i) generation of carriers due to charge compensation, (ii) reduction of sheet charge density and weakening of electrostatic attraction, and (iii) widening of the interlayer distance, all contributing to a lower Ea in K0.8M0.4Ti1.6O4. The angular frequency dependence of conductivity, dielectric permittivity (up to a colossal value of 109), and dielectric loss follows the universal power law. Our work demonstrates the potential of simple compositional variation for electrical properties tuning, prompting a more in-depth investigation covering a wider range of possible candidates of x, A+, and M in lepidocrocite titanate. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Towards the preparation of organic ferroelectric composites: fabrication of a gamma-glycine-bacterial cellulose composite via cold sintering process(2023-07-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, An architected silk fibroin-lignin multilayer with deep-level trapping states for high-output triboelectric nanogenerators(2026-03-01) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Direct synthesis and growth mechanism of metal molybdate (AMoO4; A = Ca and Ba) fine particles via the mechanochemical method(2017-08-01); Metal molybdate (AMoO<inf>4</inf>; Ca and Ba) fine particles were synthesized successfully in a simple way using the mechanochemical method under ambient conditions, without surfactants or any capping agents. The effect of milling time on phase formation and morphology was investigated. The functional group and phase formation analyses were carried out using Fourier transform infrared (FT-IR), Raman spectroscopy and X-ray diffraction (XRD) methods. XRD revealed that all samples were of a pure tetragonal scheelite structure. FT-IR and Raman analysis exhibited a Mo-O stretching peak of molecular [MoO<inf>4</inf>]<sup>2-</sup>, which related to the scheelite structure. Difference in growth mechanism and morphology was observed significantly in CaMoO<inf>4</inf> and BaMoO<inf>4</inf> particles. The primary CaMoO<inf>4</inf> nanocrystalline was formed in its initial state at 80–100 nm, and tended to aggregate into a peach-like shaped morphology with increasing milling time, while a space shuttle-like morphology formed directly via an oriented attachment mechanism for the BaMoO<inf>4</inf> particle. A possible mechanism for the formation of metal molybdate, with a different milling time, was discussed in detail. It is interesting that this work was able to present a simple way of synthesizing complex oxide materials on a large scale. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effect of Sn content on the dielectric and piezoelectric properties of the ternary system (0.975-y)BaTiO3–0.025SrTiO3–yBaSnO3(2017-06-01); ;