Now showing 1 - 10 of 23
  • Some of the metrics are blocked by your 
    Item type:Publication,
    Dielectric, ferroelectric and piezoelectric properties of the lead free 0.9BaTiO3-(0.1- x)Bi0.5Na0.5TiO3- x Bi(Mg0.5Ti0.5)O3 solid solution
    (2016-01-02)
    Mayamae, Jitkasem
    ;
    ;
    Niemchareon, Surasak
    ;
    ;
    Solid solution of 0.9BaTiO<inf>3</inf>-(0.1-x)Bi<inf>0.5</inf>Na<inf>0.5</inf>TiO<inf>3</inf>-xBi(Mg<inf>0.5</inf>Ti<inf>0.5</inf>)O<inf>3</inf> (BT-BNT-xBMT) system, where x = 0.00, 0.02, 0.04, 0.06, 0.08, 0.10, was synthesized by the solid state reaction. Dense BT-BNT-xBMT ceramics were obtained by sintering at 1,150-1,250C for 4 h. The effect of BMT on crystal structure and electrical property of BT-BNT ceramics was investigated as a function of composition, x, using X-ray diffraction, dielectric spectroscopy, hysteresis and strain measurements. The crystal structure of solid solution BT-BNT-xBMT, where x = 0.00-0.10, successively transforms from tetragonal to pseudocubic symmetry, with increased BMT concentration. Temperature dependence of dielectric constant (ε<inf>r</inf>) and dielectric loss (tanδ) for BT-BNT-xBMT at various frequencies showed that phase transition of ceramics changed from ferroelectric to relaxor-like behavior as BMT content increased. Furthermore, remanent polarization (P<inf>r</inf>), coercive field (E<inf>c</inf>) and the normalized strain (d<inf>33</inf>∗) of BT-BNT-xBMT ceramics tend to decrease with increasing BMT concentration.
  • Some of the metrics are blocked by your 
    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) ; ; ;
    Niemcharoen, Surasak
    ;
    Solid solution of the (1-x)PbZrO <inf>3</inf>-xBa(Al <inf>1/2</inf>Nb <inf>1/2</inf>)O <inf>3</inf> system, with x = 0.02-0.30, was prepared using solid state reaction. The effect of Ba(Al <inf>1/2</inf>Nb <inf>1/2</inf>)O <inf>3</inf> on phase transitions and thermal and electrical properties was investigated. The stability of ferroelectric phase in pure PZ was found to improve with increasing BAN content, which corresponded to the increased tolerance factor (t) of solid solution. In comparison to other systems, results in this study indicated that the tolerance factor can predict the ferroelectric (FE)/antiferroelectric (AFE) stability of PZ-based solid solution. If the t value of solid solution is higher than pure PZ, the FE phase can be induced. On the other hand, the AFE phase is stabilized when the t value of solid solution is lower than pure PZ. © 2012 The American Ceramic Society.
  • Some of the metrics are blocked by your 
    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) ; ; ;
    Niemcharoen, Surasak
    ;
    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 Zr<sup>4+</sup> ions were substituted by small Nb<sup>5+</sup> ions. This is due to the decreasing average rate of radii in the A-site (0.1 Å mol<sup>-1</sup>) being higher than that in the B-site (0.08 Å mol<sup>-1</sup>). © 2013 Elsevier B.V. All rights reserved.
  • Some of the metrics are blocked by your 
    Item type:Publication,
    Phase transition behavior of Ba(Mg1/3Nb2/3)O 3 modified PbZrO3 solid solution
    (2014-04-28) ; ;
    Guo, Ruyan
    ;
    Bhalla, Amar S.
    Different compositions of (1 - x)PbZrO<inf>3</inf>-xBa(Mg <inf>1/3</inf>Nb<inf>2/3</inf>)O<inf>3</inf> (PZ-BMN) system, with x = 0.00-0.50, were synthesized using the columbite precursor method. The effects of BMN content on phase transition, electrical and thermal properties of PbZrO<inf>3</inf> ceramic were investigated. The composition range and stability of the ferroelectric phase in perovskite PZ-BMN system can be improved by optimizing BMN substitution. Phase transition behavior of various solid solutions of PZ compositions can be predicted by a phase diagram established from the average electronegativity difference versus tolerance factor of the end members. © 2014 the Partner Organisations.
  • Some of the metrics are blocked by your 
    Item type:Publication,
    Cold sintering-assisted low temperature fabrication of dense Ba5Nb4O15 ceramics
    (2026-06-08) ;
    Teandam, Apichayaporn
    ;
    Pakawanit, Phakkhananan
    ;
    Kamonpha, Phitsamai
    ;
    This study presents a novel approach for fabricating Ba<inf>5</inf>Nb<inf>4</inf>O<inf>15</inf> (BNO) ceramics at low sintering temperatures via the cold sintering process (CSP), using Ba(OH)<inf>2</inf>·8H<inf>2</inf>O (BOH) as a transient liquid phase. CSP was performed under an external pressure of 10MPa with a sintering temperature range of 150°C to 300°C. Optimally, BNO-BOH ceramics achieved a relative density of 93.7 ± 0.43 when sintered at 250°C for 1h. Scanning electron microscopy (SEM) suggested that particle densification occurred via a dissolution-precipitation process, which filled pores and formed necks between particles. The study demonstrates that the residual liquid content is crucial for ceramic densification. Annealing the as-cold sintered BNO-BOH ceramics at 1000°C for 1h successfully eliminates the BaCO<inf>3</inf> secondary phase. Furthermore, dielectric properties of annealed ceramics were also characterized at room temperature from frequency range of 20Hz to 2MHz. The dielectric permittivity is reported to be 39.2 and 0.01 for tanδ at 1.8MHz. The cold sintering process provides an effective strategy to reduce the sintering temperature while achieving high relative density. This method offers a promising alternative for the fabrication of advanced ceramics.
  • Some of the metrics are blocked by your 
    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) ; ;
    Niemcharoen, Surasak
    ;
    ;
    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 your 
    Item type:Publication,
    Enhancing the densification of ceria ceramic at low temperature via the cold sintering assisted two-step sintering process
    (2018-11-01)
    Charoonsuk, Thitirat
    ;
    ;
    Kolodiazhnyi, Taras
    ;
    The cold sintering process (CSP) in the transient aqueous environment of malonic acid is applied in this study to enhance the densification behavior of ceria ceramics at a significantly reduced sintering temperature. Dense ceria ceramics (> 98% relative density) could be achieved after CSP at 180 °C, followed by the sintering at 1100 °C/4 h. As expected, the CSP can improve the compaction of the particles before sintering, resulting in ceria ceramics with a fine microstructure of submicrometer scale of grain sizes. All samples show the single phase of cubic fluorite structure with no significant change of lattice parameter. Finally, electrical conductivity of CSP and conventionally sintered ceramics is investigated. This communication emphasizes the advantage of the CSP to reduce the sintering temperature without deterioration of the structure and properties of the final ceramics.
  • Some of the metrics are blocked by your 
    Item type:Publication,
    Effect of Pb(Ni1/2W1/2)O3 on the phase transition behavior of PbZrO3 ceramic
    (2013-01-01) ; ; ;
    Niemcharoen, Surasak
    ;
    Karbkaew, Amornthep
    Solid solution of (1-x)PbZrO<inf>3</inf>-xPb(Ni<inf>1/2</inf>W <inf>1/2</inf>)O<inf>3</inf>;(1-x)PZ-xPNW ceramics, where x = 0.02-0.10, were prepared by solid state reaction. Dense (1-x)PZ - xPNW ceramics were obtained by sintering at 1,100?C for 4 h. Effect of PNW on crystal structure, phase transitions and thermal and electrical properties was investigated using X-ray diffraction, dielectric spectroscopy, hysteresis measurement and differential scanning calorimetry. The results indicated that the solubility limit of the (1-x)PZ-xPNW system was found at x = 0.04. It was proved that the intermediate phase is an antiferroelectric in the PZ-PNW system. Stability of the AFE intermediate phase was seen to improve with increasing PNW content. Copyright © 2013 Taylor & Francis Group, LLC.
  • Some of the metrics are blocked by your 
    Item type:Publication,
    Process-structure-property relationships in low-temperature microwave dielectric ceramics: from glass-assisted sintering to cold sintering for 5G/6G devices
    (2026-12-01)
    Pulphol, Phieraya
    ;
    Tang, Ying
    ;
    Fang, Liang
    ;
    ;
    With the rapid advancement of wireless communication from 5G to 6G, a pressing need has emerged for microwave dielectric ceramics with excellent performance at reduced processing temperatures, compatible with low-temperature co-fired ceramic technology. This review traces historical milestones and highlights modern design strategies for achieving optimum dielectric constant, ultra-low dielectric loss, and near-zero temperature coefficient of resonant frequency. Special emphasis is placed on recent advances in low-temperature densification routes, including sintering aids, intrinsically low-sintering-temperature ceramic families, and novel techniques like the cold sintering process. This review provides a critical analysis of the performance trade-offs inherent to each strategy, addressing the persistent challenges in achieving ultra-low loss. Furthermore, we highlight the paradigm shift toward a holistic, multifunctional design imperative for 6G systems. Finally, the transformative potential of cross-disciplinary approaches, particularly AI-assisted discovery, and computational modeling, is discussed as a key enabler for accelerating the design of next-generation, high-performance, and sustainable LTCC-compatible materials.
      1
  • Some of the metrics are blocked by your 
    Item type:Publication,
    Effect of thermal annealing on the structure of LiCoO2 powders prepared by co-precipitation method
    (2021-12-01)
    Khejonrak, Awadol
    ;
    Chanlek, Narong
    ;
    ;
    Triamnak, Narit
    ;
    Chirawatkul, Prae
    Lithium cobalt oxide (LiCoO<inf>2</inf>) powder was prepared by co-precipitation method and annealed at different temperatures of between 300 and 700 °C. The effect of annealing temperature and effect washing process with deionized water on the crystal structures of the prepared LiCoO<inf>2</inf> powders were thoroughly studied by Synchrotron powder X-Ray Diffraction (Syn-XRD), X-ray Absorption Spectroscopy (XAS), Dispersive Raman Microscopy (Raman) techniques. The change in chemical composition as a function of annealing temperature was also investigated by X-ray Photoelectron Spectroscopy (XPS) technique. The crystal structural results identified the phase evolution of the prepared LiCoO<inf>2</inf> powders upon heat treatment. The formation of HT-LiCoO<inf>2</inf> phase was observed at annealing temperature as low as 300 °C.
      1