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Structural, optical and electrical properties of the microcrystalline structure of (Ba1-xY2x/3)(Zr0.20Ti0.80)O3 ceramics
(2020-07-01)
Sumang, Rattiphorn
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Thongmee, Navavan
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Bongkarn, Theerachai
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Prasertpalichat, Sasipohn
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Kidkhunthod, Pinit
Yttrium (Y3+) doped barium zirconate titanate, (Ba<inf>1-x</inf>Y<inf>2x/3</inf>)(Zr<inf>0.20</inf>Ti<inf>0.80</inf>)O<inf>3</inf>; BYZT ceramics with varying x (0 = x ≤ 0.10) were prepared by the solid-state reaction method. These samples were analyzed by X-ray diffraction (XRD) and the XRD patterns were fitted using the Rietveld refinement. The local structural changes of the BYZT ceramics were investigated by synchrotron X-ray absorption spectroscopy. The results showed that an increase in the x content in the BYZT lattice structure significantly affected the phase transition behavior and the local structure around the Ti absorbing atoms, which corresponds with the phase transition from a tetragonal to a cubic structure. SEM images showed a uniform and highly dense microstructure with increasing x values. The optical band gap (E<inf>gap</inf>) values measured from the UV–visual diffuse reflectance spectra, showed a decrease from ~3.55 eV to ~2.90 eV with increasing values of x. The modified Curie-Weiss law showed that a normal ferroelectric phase transition is observed in the unmodified BZT ceramic and as the concentration of x increased, it induces diffuseness in the phase transition behavior. The largest dielectric constant (ε<inf>r</inf> = 13,200), the highest recoverable energy-storage density (W<inf>rec</inf> = 1.76 J/cm3) with an excellent energy storage efficiency (η = 91%) under a lower electric field of 50 kV/cm and lowest dielectric loss (tanδ = 0.01) were found in the composition of Ba<inf>0.98</inf>Y<inf>0.01337</inf>Zr<inf>0.2</inf>Ti<inf>0.8</inf>O<inf>3</inf> (x = 0.02 mol.%).
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Electrical and dielectric properties of barium titanate–polydimethylsiloxane nanocomposite with 0-3 connectivity modified with carbon nanotube (CNT)
(2019-01-02)
Nawanil, Chanisa
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Makcharoen, Worawut
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Khaosa-Ard, Krittanat
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Maluangnont, Tosapol
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Vittayakorn, Wanwilai
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.
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Effect of A-site and B-site ion replaced with small ions on the intermediate phase in PbZrO3 ceramic
(2014-02-14)
Sukkha, Usa
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Vittayakorn, Wanwilai
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Muanghlua, Rangson
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Niemcharoen, Surasak
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Vittayakorn, Naratip
The solid solution of (1 - x)PbZrO<inf>3</inf>-xNaNbO<inf>3</inf> ceramics, where x = 0.0-0.08, was synthesized by solid state reaction. The basic characterizations were performed using X-ray diffraction (XRD), dielectric spectroscopy, hysteresis measurement and differential scanning calorimetry (DSC) techniques. The results indicated that the crystal structure of the solid solution, (1 - x)PZ-xNN, where x = 0.00-0.08, is of orthorhombic symmetry. It was found that the effect of NN being replaced with small ions at the A-site and B-site can induce an AFE-like phase in PZ. The FE intermediate phase of PZ cannot be induced, although Zr4+ ions were substituted by small Nb5+ ions. This is due to the decreasing average rate of radii in the A-site (0.1 Å mol-1) being higher than that in the B-site (0.08 Å mol-1). © 2013 Elsevier B.V. All rights reserved.
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Synthesis, characterization and dielectric properties of Mn(2-x)znxP2O7 ceramics
(2013-10-29)
Sutapun, Manoon
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Muanghlua, Rangson
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Niemcharoen, Surasak
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Vittayakorn, Wanwilai C.
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Seeharaj, Panpailin
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 Zn2+ 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> 4- 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.
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Phase transition behaviour and electrical properties of lead-free (K 0.5Na0.5)NbO3-LiNbO3-LiSbO 3 piezoelectric ceramics
(2011-05-01)
Muanghlua, Rangson
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Niemcharoen, Surasak
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Sutapun, Manoon
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Boonchom, Banjong
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Vittayakorn, Naratip
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.
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Phase transition and dielectric properties of lead free (K 0.5Na0.5)NbO3- Bi(Zn0.5Ti 0.5)O3 piezoelectric ceramics
(2009-12-01)
Sutapun, Manoon
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Vittayakorn, Naratip
Lead-free piezoelectric ceramics of (1-x)(K0.5Na0.5) NbO3 - x(Bi(Zn0.5Ti0.5)O3; x = 0.00-0.30 were prepared via the two-stage mixed oxide fabrication technique. The crystal structure and ferroelectric phase transitions were studied by means of x-ray diffraction and thermal measurements. XRD results showed that a single-phase perovskite structurewas formed in the ceramics with x ≤ 0.25. For the ceramics with x = 0.30, a small amount of secondary phase Bi2Ti2O7 with a cubic structure was formed. The ceramics with a perovskite structure showed an orthorhombic phase at 0.00 ≤ x ≤ 0.010 and became rhombohedral at 0.010 < x ≤ 0.015 before transforming to a cubic phase at 0.015 < x ≤ 0.25. In addition, DSC results showed that the phase transition temperature of orthorhombic-tetragonal (TO-T) and tetragonal-cubic (TC) decreased when a small amount of BZT was added. The trend of enthalpy for orthorhombic → tetragonal phase transition and tetragonal → cubic phase were found to reduce with progressive increases in small amounts of BZT content. This behavior could originate from the more complex occupation of the A and B sites in an ABO3 perovskite structure. Copyright © Taylor & Francis Group, LLC.
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Preparation and properties of lead free bismuth sodium titanate-bismuth zinc titanate ceramics
(2009-12-01)
Muanghlua, Rangson
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Niemcharoen, Surasak
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Vittayakorn, Wanwilai C.
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Tungsitvisetkul, Nattapong
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Chinwaro, Pimjan
Lead-free piezoelectric ceramics based on (1-x)Bi1/2Na1/2TiO3 - x Bi(Zn1/2 Ti1/2)O3 (x = 0.0, 0.02, 0.04, 0.06, 0.08, 0.10, 0.20, 0.30, 0.40, and 0.5) were obtained via solid-state processing techniques. The influence of BZT addition on BNT characteristics, sintering, microstructure and properties was investigated. A single perovskite phase with rhombohedral symmetry was obtained for Bi(Zn1/2Ti1/2)O3 substitutions of up to 10 mole%. A small amount of BZT was effective for improving both sintering behavior and dielectric properties of BNT ceramics. Optimized dielectric properties were obtained for samples with a maximum density of ρ = 98.3% for the composition, x = 0.1. Copyright © Taylor & Francis Group, LLC.
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Phase transitional behavior and dielectric properties of lead free (1-x)(K0.5Na0.5)NbO3-xBi (Zn0.5Ti0.5)O3 ceramics
(2009-06-24)
Sutapun, Manoon
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Huang, Chien Chih
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Cann, David P.
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Vittayakorn, Naratip
Lead-free ceramics based on potassium sodium niobate [(K<inf>0.5</inf>Na<inf>0.5</inf>)NbO<inf>3</inf>; KNN]-bismuth zinc titanate [Bi(Zn<inf>0.5</inf>Ti<inf>0.5</inf>)O<inf>3</inf>; BZT] were prepared by the modified-conventional mixed oxide route with normal sintering. The crystal structure and ferroelectric phase transitions were studied by means of X-ray diffraction, thermal and dielectric measurements. The ceramics with perovskite structure were in orthorhombic phase at x ≤ 0.010. When reaching 0.01 < x ≤ 0.03, they became a rhombohedral perovskite structure; and with increasing BZT content, cubic within the studied composition range. The phase Bi<inf>2</inf>Ti<inf>2</inf>O<inf>7</inf> with cubic structure began to appear at x > 0.25 and became dominant while increasing the content of BZT. Furthermore, the phase transition temperature of orthorhombic-tetragonal (T<inf>O-T</inf>) and tetragonal-cubic (T<inf>C</inf>) decreased when a small amount of BZT was added. As the amount of BZT concentration increased, the structure became denser, and well developed grain morphology with almost no porosity was finally obtained. © 2008 Elsevier B.V. All rights reserved.
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Synthesis and properties of Pb(Co1/3Nb2/3)O3 ceramics
(2008-10-20)
Unruan, Muangjai
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Vittayakorn, Naratip
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Wongmaneeruang, Rewadee
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Prasatkhetragarn, Anurak
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Ananta, Supon
In this study, Pb(Co<inf>1/3</inf>Nb<inf>2/3</inf>)O<inf>3</inf> or PCN ceramics have been produced by sintering PCN powders synthesized from lead oxide (PbO) and cobalt niobate (CoNb<inf>2</inf>O<inf>6</inf>) with an effective method developed for minimizing the level of PbO loss during sintering. Attention has been focused on relationships between sintering conditions, phase formation, density, microstructural development, dielectric and ferroelectric properties of the sintered ceramics. The densities of sintered PCN ceramics increased with increasing sintering temperature. However, it was observed that at too high temperature the density began to decrease. Change of dielectric properties with sintering temperature also followed the same trend as the density. Based on X-ray diffraction analysis, density data, SEM micrograph, and dielectric properties, the optimum sintering temperature for a high purity PCN ceramic was found to be about 1100 and 1150 °C. A strongly diffused dielectric peak also showed a typical characteristic of ferroelectric relaxors. The P-E hysteresis loops observed at -70 °C were of slim-loop type with small remnant polarization values, which confirmed relaxor ferroelectric behavior of PCN ceramics. © 2007 Elsevier B.V. All rights reserved.
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The effect of post-sintering annealing induced extrinsic dielectric properties in PZT-PZN ceramics
(2007-08-02)
Vittayakorn, Naratip
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Cann, David P.
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Rujijanagul, Gobwute
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Tunkasiri, Tawee
Pb[(Zr1/2Ti1/2)0.7(Zn1/3Nb2/3)0.3]O3 (PZT-30PZN) powder was prepared using the columbite precursor method. The phase development of calcined powder precursors was analyzed by X-ray diffraction. Dielectric and ferroelectric properties of the as-sintered and annealed samples were measured and correlated with microstructure. The morphology evolution was determined by a scanning electron microscopy (SEM) technique. The as-sintered ceramic exhibited weak relaxor-ferroelectric behavior, with a relatively low dielectric constant maximum measured at 1 kHz (Km@1 kHz) of 14 000. Annealing resulted in a transition to normal-ferroelectric-like behavior, a shift in the dielectric maximum temperature from 310C to 300C, and a dramatic increase of Km@1 kHz to a maximum value of 25 100 for the longer anneal. After thermal annealing at 900C for 1 week a strong enhancement of remanent polarization (Pr) was observed.

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