Vittayakorn, Naratip
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Vittayakorn, Naratip
Alternative Name
Vittayakorn, N.
Vittayakorn, Narathip
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naratip.vi@kmitl.ac.th
24 results
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Item type:Publication, Electrical properties of bismuth potassium titanate-strontium titanate ferroelectric ceramics(2010-07-30); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Phase transition behaviour and electrical properties of lead-free (K 0.5Na0.5)NbO3-LiNbO3-LiSbO 3 piezoelectric ceramics(2011-05-01); ; The ternary system of 0.945(K<inf>0.5</inf>Na<inf>0.5</inf>NbO <inf>3</inf>)-(0.055 - x)LiNbO<inf>3</inf>-xLiSbO<inf>3</inf> [0.945KNN-(0.055 - x)LN-xLS]; x = 0.0-0.055 lead-free piezoelectric ceramics was fabricated by the conventional mixed oxide method with normal sintering. The crystal structure was studied by means of X-ray diffraction (XRD). The results of XRD patterns show that complete solid solutions of the mixed phase between the orthorhombic and tetragonal perovskite phase were observed. The DSC and dielectric data show that the amount of LiSbO<inf>3</inf> in K<inf>0.5</inf>Na<inf>0.5</inf>NbO <inf>3</inf>-LiNbO<inf>3</inf> solid solution slightly decreases the paraelectric cubic-ferroelectric tetragonal phase transition (T<inf>C</inf>) to a low temperature. Furthermore, good dielectric and piezoelectric properties were observed at composition, x = 0.03. The polymorphic phase transition between the orthorhombic and tetragonal phases plays a very important role in enhancement of the piezoelectric properties of KNN-LN-LS ceramics. © 2010 Elsevier B.V. All rights reserved. - 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, Non-isothermal kinetics of the thermal decomposition of sodium oxalate Na2C2O4(2012-03-01); ; The thermal transformation of Na<inf>2</inf>C<inf>2</inf>O<inf>4</inf> was studied in N<inf>2</inf> atmosphere using thermo gravimetric (TG) analysis and differential thermal analysis (DTA). Na<inf>2</inf>C<inf>2</inf>O<inf>4</inf> and its decomposed product were characterized using a scanning electron microscope (SEM) and the X-ray diffraction technique (XRD). The non-isothermal kinetic of the decomposition was studied by the mean of Ozawa and Kissinger-Akahira-Sunose (KAS) methods. The activation energies (Eα) of Na<inf>2</inf>C<inf>2</inf>O<inf>4</inf> decomposition were found to be consistent. Decreasing Eα at increased decomposition temperature indicated the multi-step nature of the process. The possible conversion function estimated through the Liqing-Donghua method was 'cylindrical symmetry (R <inf>2</inf> or F<inf>1/2</inf>)' of the phase boundary mechanism. Thermodynamic functions (DH*, DG* and DS*), calculated by the Activated complex theory and kinetic parameters, indicated that the decomposition step is a high energy pathway and revealed a very hard mechanism. © Akadémiai Kiadó, Budapest, Hungary 2011. - 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, Influence of Pb(In1/2Nb1/2)O3 on the phase transitions, electrical, and thermal properties of a PbZrO3 ceramic(2011-10-01); ; ; The solid solution of a (1-x)PbZrO<inf>3</inf>-xPb(In<inf>1/2</inf>Nb <inf>1/2</inf>)O<inf>3</inf> (PZ-PIN) system, with x=0.00-0.50, was synthesized using the wolframite precursor method. The effects of the PIN content on the crystal structure, and the electrical and thermal properties of a PbZrO <inf>3</inf> ceramic were investigated using X-ray diffraction, dielectric spectroscopy, hysteresis measurement, and differential scanning calorimetry techniques. Furthermore, the morphology and grain size were determined using scanning electron microscopy. The results indicated that the pure perovskite phase was obtained for all compositions, and the solid solution, PZ-PIN, changed from orthorhombic to rhombohedral symmetry when the amount of PIN increased. A ferroelectric intermediate phase began to appear between the paraelectric and the antiferroelectric phases of pure PZ, with increasing PIN content. The temperature range width of the ferroelectric phase also increased continuously with increasing PIN. At room temperature, the polymorphic phase transition (PPT) was identified from the orthorhombic to the rhombohedral phase in (1-x)PZ-xPIN at the composition, x=0.40. The ceramics (x=0.40) with PPT close to room temperature exhibited excellent electrical properties (ε<inf>rmax</inf>= 33240 and P<inf>r</inf>=26.94 μC/cm<sup>2</sup>). © 2011 The American Ceramic Society. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, The phase evolution with temperature in 0.94PbZrO3-0. 06Pb(Mg1/2W1/2)O3 antiferroelectric ceramic(2010-09-10); ; - 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, Effect of Pb(Y1/2Nb1/2)O3 additions on thermal and electrical properties of PbZrO3 ceramics(2011-07-29); ; ; The solid solution of a (1-x)PbZrO<inf>3</inf> - xPb(Y<inf>1/2</inf>Nb <inf>1/2</inf>)O<inf>3</inf> (PZ - PYN) system, with x = 0.00 - 0.08, was synthesized by the wolframite precursor method. The effects of PYN content on crystal structure, and electrical and thermal properties of PbZrO<inf>3</inf> ceramic were investigated. The crystal structure of sintered ceramics was characterized by X-ray diffraction. The pure perovskite phase was obtained for all compositions. The transition temperatures of the AFE to PE phase become lower with PYN increase. The dielectric properties of PZ were improved by the addition of PYN. Copyright © Taylor & Francis Group, LLC. - 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.