Vittayakorn, Wanwilai
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Preferred name
Vittayakorn, Wanwilai
Alternative Name
Vittayakorn, W.
Vittayakorn, Wanwilai C.
Main Affiliation
Email
wanwilai.vi@kmitl.ac.th
13 results
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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, Preparation of lead zirconate-lead nickel niobate ceramics by the reaction sintering process(2009-12-01); ; ; Laoratanakul, PitakThe perovskite structure of lead zirconate - lead nickel niobate ceramics, (1-x) PbZrO3-xPb(Ni1/3Nb2/3)O3 (PZ - PNN) at x between 0.00-0.50, has been prepared by the reaction-sintering process. The specimens were prepared directly from a mixture of their constituent oxide without any calcination step. The PZ - PNN ceramics could be obtained after 6 h sintering at 1,100-1,250°C. Crystal structure and phase transition of PZ-PNN were investigated by x-ray diffraction (XRD). XRD indicated that the structure of PZ-PNN ceramics is orthorhombic for a composition where x = 0.00, rhombohedral for compositions where x = 0.10 ≤ x ≤ 0.40 and pseudo-cubic for a composition where x = 0.50. The dielectric properties of the ceramics were measured as functions of both temperature and frequency. The results indicated that the transition temperature decreases with increasing PNN concentration. Furthermore, morphology and grain size evolution have been determined via a scanning electron microscope (SEM). Copyright © Taylor & Francis Group, LLC. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Fine Grain BaTiO3-Co0.5Ni0.5Fe2O4 Ceramics Prepared by the Two-Stage Sintering Technique(2015-10-30); ; This work investigated the improvement of density and controllable grain size of multiferroic ceramics by using the system of (0.8)BaTiO<inf>3</inf>-(0.2)Co<inf>0.5</inf>Ni<inf>0.5</inf>Fe<inf>2</inf>O<inf>4</inf> nanocomposites via the two-stage sintering technique. The sintering process was divided into two steps. Firstly, samples were fired at the optimized temperature of T<inf>1</inf> to activate grain boundary migration in order to obtain an initial high density. Secondly, the samples were cooled immediately to the temperature of T<inf>2</inf> and soaked at various times to enable dense ceramics without grain growth. All of the samples were characterized by an X-ray diffractometer, and the results confirmed that all samples were composite ceramics. Scanning electron microscopy showed the grain size of all the samples and proved that the two-stage sintering technique achieved fine grain ceramics when compared with traditional sintering. Electrical properties of all the samples were investigated using an LCR meter at room temperature to 200°C with various frequencies, and magnetic properties were characterized by a vibrating sample magnetometer. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Synthesis, characterization and dielectric properties of Mn(2-x)znxP2O7 ceramics(2013-10-29); ; Manganese zinc pyrophosphate (Mn<inf>(2-x)</inf>Zn<inf>x</inf>P<inf>2</inf>O<inf>7</inf> when x = 0.0, 0.5, 1.0, 1.5 and 2.0) ceramics were fabricated by conventionally mixing oxide using the normal sintering method. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Raman spectroscopy and scanning electron microscopy (SEM). The XRD results indicated that synthesized Mn<inf>(2-x)</inf>Zn<inf>x</inf>P<inf>2</inf>O<inf>7</inf> systems have a pure monoclinic phase without the presence of phase impurities. The lattice parameters and crystalline sizes analyzed from XRD data were changed depending on the amount of added Zn<sup>2+</sup> ion concentration in the Mn<inf>2</inf>P<inf>2</inf>O<inf>7</inf> structure. The FT-IR and Raman results showed the fundamental vibrations of P<inf>2</inf>O<inf>7</inf> <sup>4-</sup> ion and Mn-O or Zn-O, which confirmed the Mn<inf>(2-x)</inf>Zn<inf>x</inf>P<inf>2</inf>O<inf>7</inf> formation. In addition, dielectric stability of temperature and frequency was observed in the composition, x = 1.0, with a dielectric constant value of 11.5 at 1 MHz. © (2013) Trans Tech Publications, Switzerland. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Preparation and properties of lead free bismuth sodium titanate-bismuth zinc titanate ceramics(2009-12-01); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Phase transition behavior of the (1-x) PbZrO 3-x Ba (Al 1/2 Nb 1/2) O 3 solid solution(2012-10-01); ; ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Synthesis and morphology evolution of lead-free piezoelectric K 1/2Na1/2NbO3 powder at low temperature(2009-12-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effect of A-site and B-site ion replaced with small ions on the intermediate phase in PbZrO3 ceramic(2014-02-14); ; ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effect of Pb (Yb 1/2Nb 1/2)O 3 on phase transition and thermal and electrical properties of PZ-PYbN solid solution on PZ-rich side(2012-02-01); ; ; The (1 - x)PbZrO <inf>3</inf>-xPb(Yb <inf>1/2</inf>Nb <inf>1/2</inf>)O <inf>3</inf> (PZ-PYbN) ceramics, with the compositions, x = 0.00-0.50, were prepared by the wolframite precursor method. The crystal structure and electrical and thermal properties of PbZrO <inf>3</inf> ceramic were investigated as a function of the composition, x, using X-ray diffraction, dielectric spectroscopy, hysteresis measurement and differential scanning calorimetry techniques. The results indicated that the solid solution, PZ-PYbN, changed from orthorhombic to rhombohedral symmetry when the amount of PYbN increased. The pyrochlore phase identified as Yb/Nb mixed compound was observed at the composition, x ≥ 0.2. For the compositions, x = 0.00-0.10, ceramics showed a sharp phase transition from AFE to PE. Furthermore, the intermediate FE phase was absent from the PZ-PYbN system. © 2011 Springer Science+Business Media, LLC. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Sonochemical synthesis of spherical BaTiO3 nanoparticles(2013-01-01); ; Monosized spherical barium titanate (BaTiO<inf>3</inf>) nanoparticles have been synthesized successfully via sonochemical reaction. The as-synthesized BaTiO<inf>3</inf> nanoparticles were characterized using X-ray diffraction of powder, Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy. The XRD pattern of BaTiO<inf>3</inf> particles, which were synthesized under irradiation of ultrasonic sound for 0.5 h, showed sharp diffraction peaks that corresponded to the cubic BaTiO<inf>3</inf> phase. Only a small amount of BaCO<inf>3</inf> contamination was present in the sample. The Raman active modes of the samples in this study were similar to the cubic phase of BaTiO<inf>3</inf>. The average diameter of sonochemical synthesized particles was ∼99.54 ± 18.25 nm. The synthesized BaTiO<inf>3</inf> nanoparticles were almost spherical. © 2013 Copyright Taylor and Francis Group, LLC.