Wirunchit, Supamas
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Wirunchit, Supamas
Alternative Name
Wirunchit, S.
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supamas.wi@kmitl.ac.th
9 results
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Item type:Publication, Structural transformation in antiferroelectric PbZrO3-relaxor ferroelectric Pb(Ni1/3 Nb2/3)O3 solid solution system(2008-08-12); The solid solution between the antiferroelectric (AFE) PbZrO<inf>3</inf> (PZ) and the relaxor ferroelectric (FE) Pb (Ni<inf>1/3</inf>Nb <inf>2/3</inf>)O<inf>3</inf> (PNN) was synthesized by the columbite precursor method. The crystal structure, phase transformations, and dielectric and thermal properties of (1-x) PZ-xPNN where x=0.00-0.30 were investigated. With these data, the FE phase diagram between PZ and PNN has been established. The crystal structure data obtained from X-ray diffraction indicate that the solid solution PZ-PNN, where x=0.00-0.30, successively transforms from orthorhombic to rhombohedral symmetry with an increase in the PNN concentration. The AFE phase→FE phase transition occurs in compositions of 0.00≤x≤0.08. The AFE→FE phase transition shifts to lower temperatures with higher compositions of x. The FE phase temperature range width increases with increased PNN. Apparently the replacement of the Zr<sup>4+</sup> ion by Ni <sup>2+</sup>/Nb<sup>5+</sup> ions decreases the driving force for an antiparallel shift of Pb<sup>2+</sup> ions because they interrupt the translational symmetry and facilitates the appearance of a rhombohedral FE phase when the amount of PNN is higher than 8 mol %. © 2008 American Institute of Physics. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Physical properties and phase transitions in perovskite Pb[Zr 1-x(Ni1/3Nb2/3)x]O3 (0.0 ≤ x ≤ 0.5) ceramics(2008-06-21); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, High temperature phases in the 0.98 PbZrO3 -0.02Pb (Ni 1/3Nb2/3) O3 ceramic(2009-07-09); ; Besser, M. F.The phase evolution with temperature in the 0.98 PbZrO<inf>3</inf> -0.02Pb (Ni<inf>1/3</inf>Nb<inf>2/3</inf>) O<inf>3</inf> ceramic was investigated with dielectric permittivity and polarization measurements, hot stage transmission electron microscopy, and high temperature x-ray diffraction. Below 190 °C, the ceramic is in the antiferroelectric phase with characteristic 1 4 { 110 } c superlattice diffractions. In this stage, typical antiferroelectric 180° domains were observed. Between 190 and 220 °C, an intermediate phase, which is characterized by 1 2 { 110 } c -type superlattice diffractions, was detected. Evidences are found to suggest that this intermediate phase is ferroelectric. The 1 2 { 110 } c -type superlattice diffraction persists even into the paraelectric phase above 220 °C. In addition, there exists an incommensurate phase between the low temperature antiferroelectric phase and the intermediate ferroelectric phase. © 2009 American Institute of Physics. - 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, Perovskite formation, dielectric and ferroelectric properties of PbZrO 3-Pb(Ni1/3Nb2/3)O3 ceramics via a columbite precursor synthetic route(2007-06-01); Perovskite structures in the PZ-PNN system with formula (1-x)PbZrO <inf>3</inf>-xPb(Ni<inf>1/3</inf>Nb<inf>2/3</inf>)O<inf>3</inf> with x ≤ 0.0-0.5 are synthesized via the columbite precursor technique. The formation of the perovskite phase in the calcined powders has been investigated as a function of calcination conditions by using thermogravimetric and differential thermal analysis (TG-DTA) and x-ray diffraction (XRD) techniques. The complete solid solutions of the perovskite phase of PZ-PNN ceramics were obtained over a wide compositional range. It was observed that for the binary system (1-x)PbZrO <inf>3</inf>-xPb(Ni<inf>1/3</inf>Nb<inf>2/3</inf>)O<inf>3</inf>, the change in the calcination temperature is approximately linear with respect to the PNN content in the range x ≤ 0.0-0.5. With increasing x, the calcination temperature shifts forward to high temperatures. It is seen that optimization of the calcination conditions can lead to a 100% yield of PZ-PNN in a pseudo-cubic phase. The P-E hysteresis loop measurements demonstrated that the ferroelectric properties of the ceramics in the PZ-PNN system changed gradually from normal ferroelectric behavior to relaxor ferroelectric behavior with increasing PNN concentration. In addition, the squareness of the hysteresis loop (R <inf>sq</inf>) decreased quasi-linearly as the molar fraction of PNN increased. The maximum spontaneous polarization (P<inf>s</inf>) and remanent polarization (P<inf>r</inf>) for the x ≤ 0.1 composition were 31.6νCcm<sup>-2</sup> and 27.8νCcm<sup>-2</sup>, respectively. These results clearly show the significance of PNN in controlling the electrical responses of the PZ-PNN system. © IOP Publishing Ltd. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effect of lead nickel niobate substitution on phase transitions of lead zirconate ceramics prepared by the solid state reaction method(2008-01-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Crossover from antiferroelectric to normal ferroelectric behavior in lead zirconate - lead nickel niobate ceramics prepared by the reaction sintering process(2009-12-01); The lead zirconate - lead nickel niobate ceramics, (1-x)PbZrO3 - xPb(Ni1/3Nb2/3)O3 (PZ-PNN) with x = 0.00-0.10, have been prepared by reaction sintering. Without any calcination involved, the mixture of raw materials was pressed and sintered directly. The PZ-PNN ceramics could be obtained after 6 h sintering at 1,100-1,250°C. The crystal structure data obtained from XRD indicate that the PZ-PNN, where x = 0.00-0.10, successively transforms from orthorhombic to rhombohedral symmetry with an increase in the PNN concentration around x = 0.08. The antiferroelectric phase (AFE) → ferroelectric phase (FE) transition occurs in compositions of 0.0 ≤ x ≤ 0.08. The AFE → FE phase transition shifts to lower temperatures with higher compositions of x. The FE phase temperature range width increases with increased PNN. Copyright © Taylor & Francis Group, LLC. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Perovskite phase formation, phase transformations and electrical properties of lead-nickel niobate - Lead zirconate ceramics(2007-12-01); ; ; Niemcharoem, SusasakThe perovskite structure of lead zirconatelead nickel niobate ceramics, (1-x)PbZrO3-xPb(Ni1/3Nb2/3)O3 (PZ - PNN) with x = 0.0-0.5, were synthesized via the columbite precursor method. The formation of the perovskite phase in the calcined powders has been investigated as a function of calcination conditions by TG-DTA and XRD techniques. The complete solid solutions of perovskite phase of PZ-PNN ceramics were obtained over a wide compositional range. The results showed that the concentration of the PNN phase increased the calcination temperature must be increased in order to obtain phase-pure perovskite. In addition, x-ray diffraction indicated a phase transformation from a orthorhombic to a pseudo-cubic phase when the fraction of PNN was increased. A higher relative permittivity value, as a consequence of the higher PNN concentration, was observed. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Dielectric properties and phase transition behaviors in (1-x) PbZrO3 -xPb (Mg1/2 W1/2) O3 ceramics(2009-10-09); ; The solid solution of lead zirconate [PbZrO3 (PZ)] and lead magnesium tungstate [Pb (Mg1/2 W1/2) O<sup>3</sup> (PMW)] has been synthesized by the wolframite precursor method. The crystal structure, phase transformations, dielectric and thermal properties of (1-x) PZ-xPMW, where x=0.00-0.10, were investigated. The crystal structure of sintered ceramics was analyzed by x-ray diffraction. Phase-pure perovskite was obtained for all compositions. Furthermore, a change from orthorhombic to rhombohedral symmetry was observed as the mole fraction of increased PMW. As a result, it was found that PbZrO <sup>3</sup> -Pb (Mg1/2 W1/2) O<sup>3</sup> undergoes successive transitions from the antiferroelectric phase to the ferroelectric phase to the paraelectric state. The coexistence of orthorhombic and rhombohedral phases in this binary system is located near the composition x=0.1. © 2009 American Institute of Physics.