Vittayakorn, Naratip
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Vittayakorn, Naratip
Alternative Name
Vittayakorn, N.
Vittayakorn, Narathip
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naratip.vi@kmitl.ac.th
18 results
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Item type:Publication, Phase formation, microstructure and electrical properties of Ba0.9Ca0.1TiO3 ceramics fabricated via the solid-state combustion technique(2022-01-01) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, The effect of excess PbO on crystal structure, microstructure and dielectric properties of (Pb0.50Sr0.50)TiO3 ceramics(2013-01-01); Bongkarn, TheerachaiLead strontium titanate [(Pb5<inf>0</inf>Sr5<inf>0</inf>)TiO<inf>3</inf>; PST] ceramics were fabricated by the conventional solid state reaction method using calcination and sintering temperatures of 950°C and 1250°C. To prevent PbO evaporation during the firing processes, excess PbO was added to the samples in varying amounts from 0-10 wt.%. It was found that PST powders indexed in a tetragonal structure. Impurity phases were detected in the calcined powders which had excess PbO higher than 3 wt%. A pure perovskite phase was obtained from all ceramic samples. The lattice parameters a, c and the c/a ratio decreased with an increasing excess of PbO. The average particle size and the average grain size increased with the increase of PbO. The porous microstructure slightly decreased with an increasing amount of PbO, up to 1 wt.%, then slightly increased with higher excess PbO. The density can be improved by adding 1 wt.% of excess PbO. The dielectric constant increased from 7500 for the 0 wt.% sample to 8300 for the 1 wt%. This was followed by reductions for 3, 5 and 10wt.%. The Curie temperature and transition enthalpy slightly increased with an increase amount of PbO until 1 wt.%, then slightly decreased, for the higher excess PbO. © 2013 Copyright Taylor and Francis Group, LLC. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Crystal structure, microstructure and electrical properties of (1-x-y)Bi0.5Na0.5TiO3-xBi0.5K 0.5TiO3-yBiFeO3 ceramics near MPB prepared via the combustion technique(2013-05-01); Bongkarn, Theerachai(1-x-y)Bi<inf>0.5</inf>Na<inf>0.5</inf>TiO<inf>3</inf>-xBi <inf>0.5</inf>K<inf>0.5</inf>TiO<inf>3</inf>-yBiFeO<inf>3</inf> (BNKFT-x/y with 0.12≤x≤0.24, 0≤y≤0.07) lead-free piezoelectric ceramics have been prepared by the combustion technique. The effects of amounts of x and y on structures and electrical properties were examined. Powders and ceramics can be well calcined and sintered at 750 °C for 2 h and 1025-1050 °C, respectively. The results indicated that the crystalline structure and microstructure changed with the increase of x and y concentrations. XRD results of BNKFT-x/0.03 and BNKFT-0.18/y ceramics with 0.12≤x≤0.24 and 0≤y≤0.07 showed the rhombohedral-tetragonal morphotropic phase boundary (MPB). The addition of y caused a promoted grain growth while the addition of x suppressed the grain growth. The highest density (ρ=5.85 g/cm<sup>3</sup>), superior dielectric properties at T<inf>c</inf> (ε<inf>r</inf>=7846 and tan δ=0.02), remnant polarization measured at 40 kV/cm (P<inf>r</inf> = 20.1 μC/cm<sup>2</sup>) and piezoelectric coefficient (d<inf>33</inf>=213 pC/N) were obtained for x=0.18 and y=0.03. © 2012 Elsevier Ltd and Techna Group S.r.l. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Fabrication of BNBT-BS ceramics via a solid-state combustion approach for BNBT-BS/PDMS composite films in hybrid PENG/TENG applications(2026-10-01) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, ADSORPTION OF HEAVY METALS USING BIO-CALCIUM CARBONATE DERIVED FROM A GOLDEN APPLE SNAIL (GAS) SHELL(2023-01-01); Sumang, RattiphornIn this research studied the use of calcium carbonate (CaCO<sup>3</sup>) from golden apple snail (GAS) shells for application as an absorbent material to remove heavy metals in water sources, which replaces commercial calcium carbonate (CaCO<sup>3</sup>) to reduce production costs and increase waste value. The adsorption of heavy metal contents (such as lead; Pb and Cadmium; Cd), phase formation, and physical characterization of golden apple snail shells were investigated for use as a calcium source in the production of naturally based biomaterials. The samples were calcined between 700°C and 950°C for 5 hr. TG and DTA analysis of samples demonstrated the decomposition of CaCO<sup>3</sup> to CaO. The XRD results demonstrated that natural shell powder has a crystal phase of CaCO<sup>3</sup> with an aragonite structure. Furthermore, the CaCO<sup>3</sup> (calcite phase) was transformed into calcium oxide (CaO) as a component, which showed that the phase transformation depended on the calcination temperature. The adsorption experiments showed good performance at about 99.6%, 99.7%, and 97% removal efficiency in a shorter time for calcined GAS at 700, 800, and 900°C, respectively. This study suggests that the golden apple snail shell could be an effective biomaterial for heavy removal from contaminated water. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Integration of CCTAO/PDMS composite films into proximity capacitive sensor devices(2026-12-01); Pakawanit, PhakkhanananFlexible capacitive proximity sensors are promising for contactless sensing applications, but their performance is strongly influenced by the dielectric properties and microstructure of the sensing layer. In this work, CaCu<inf>3</inf>Ti<inf>4-x</inf>A<inf>x</inf>O<inf>12</inf>/polydimethylsiloxane (CCTAO/PDMS, A = Nd<sup>3+</sup> or Gd<sup>3+</sup>) composite films were developed as flexible dielectric layers for interdigitated capacitive proximity sensors. Nd- and Gd-doped CCTO ceramics were synthesized by a solid-state reaction method and incorporated into a PDMS matrix at different filler loadings. Structural analysis confirmed that the CCTAO ceramics retained the cubic CCTO phase after rare-earth substitution, while the composite films preserved the characteristic amorphous structure of PDMS with embedded ceramic fillers. The FESEM, EDS mapping and X-ray tomographic microscopy analyses showed that the CCTNdO/PDMS composite had a more uniform distribution of ceramic particles than the CCTO/PDMS system. The dielectric measurements demonstrated the improvement in the dielectric constant of the PDMS-based composites upon CCTNdO incorporation and also indicated that the composites did not exhibit any significant changes in their dielectric properties across the range of frequencies examined. The CCTNdO/PDMS films were found to show the negative capacitance response as a function of distance due to the electric-field shunting mechanism when used in an interdigitated capacitor sensor. The sensor with composition 10 wt% CCTNdO/PDMS had excellent performance with a maximum normalized capacitance change equal to −8.70%, which corresponds to a proximity sensitivity of around 0.42%/mm and an effective sensing range of around 20 mm. It is concluded that the optimization of the loading of the rare-earth material in a flexible PDMS matrix is an effective approach to achieve a compromise between the dielectric enhancement of the sensor and the dispersion of the filler and fringing-field interaction in the contactless capacitive proximity sensor. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Synthesis and Characterization of KNN Modified BNT-ST Ceramics for Energy Storage Applications(2021-01-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Multiferroic Properties of (1-x)BiFeO3-xBaTiO3 Lead-Free Ceramics(2023-01-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, High-performance triboelectric and piezoelectric nanogenerator enabled by BF-BT-NZN multifunctional ceramic filler(2025-10-01); Bongkarn, TheerachaiThe development of efficient and flexible energy-harvesting materials is essential for advancing self-powered electronic devices. In this study, we report the fabrication of flexible composite films by incorporating (1-x)(0.75BiFeO<inf>3</inf>-0.25BaTiO<inf>3</inf>)-xNd(Zn<inf>0.67</inf>Nb<inf>0.33</inf>)O<inf>3</inf>,abbreviated as (BF-BT-NZN), ceramic powder into a PDMS matrix, with filler contents ranging from 5 to 25 wt%. The optimized 10 wt% composite film demonstrated a maximum output voltage of 112.24 V and a current of 5.69 µA approximately 11 and 18 times higher than pure PDMS, respectively. Following a poling treatment, the output further increased to 149.54 V and 10.71 µA. The film exhibited excellent flexibility and durability, enabling practical applications such as powering LEDs, a digital watch, and charging capacitors. These results highlight the potential of BF-BT-NZN/PDMS composites as high-performance materials for wearable energy-harvesting applications. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Preparation of BST Powders and Ceramics via a Hybrid Method(2023-01-01); Sumang, RattiphornBarium strontium titanate (Ba<inf>0.8</inf>Sr<inf>0.2</inf>TiO<inf>3</inf>; BST) ceramics, were prepared by the hybrid method between Solid-state reaction (SSR) and Sol-gel methods (SG) in a ratio of 1:0.1–1:0.5. The BST powder was successfully calcined at 850 °C for 2 h. This temperature is much lower than the calcination temperatures of the SSR method. The BST ceramics were sintered between 1150 and 1450 °C. All samples showed the pure perovskite structure corresponding to JCPDS no. 34-0411. The optimum sintering temperature was observed from the samples sintered at 1450 °C for 4 h, indicating a density of 5.26 g/cm<sup>3</sup>, dielectric constant of 7018, and ferroelectric properties: (P <inf>max</inf> = 13.8 μC/cm<sup>2</sup>, P <inf>r</inf> = 2.5 μC/cm<sup>2</sup> and E <inf>c</inf> = 2.3 kV/cm at 30 kV/cm).