KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Settings

Access type: UnknownAuthor: search.filters.author.Julphunthong, Phongthorn

Search Results

Now showing 1 - 3 of 3
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Modified energy storage properties of lead-free Sr0.3Bi0.35Na0.335Li0.015TiO3 ceramics with La3+ substitution via the solid-state combustion technique
    (2024-12-01)
    Sinkruason, Thanapon
    ;
    Luangpangai, Anupong
    ;
    Julphunthong, Phongthorn
    ;
    Rittidech, Aurawan
    ;
    Suthapintu, Aekasit
    In this study, the influence of La<sup>3+</sup> substitution on the phase structure, microstructure, electrical and energy storage properties of (Sr<inf>0.3</inf>Bi<inf>0.35</inf>Na<inf>0.335</inf>Li<inf>0.015</inf>)<inf>1-x</inf>La<inf>x</inf>TiO<inf>3</inf> (SBNLT-xLa) ceramics with x = 0–0.05, using the solid-state combustion technique, was investigated. X-ray diffraction (XRD) patterns indicated a pure perovskite structure formed, along with coexisting rhombohedral and tetragonal phases in all ceramics. The Rietveld refinement analysis showed the tetragonal phase increased while the rhombohedral phase decreased with increased La<sup>3+</sup> content. The morphology of the SBNLT-xLa ceramics displayed polygonal grain shapes and anisotropic grain growth. Average grain sizes increased from 2.01 to 2.43 μm as x increased from 0 to 0.01 and afterwards decreased as x increased further. Both the measured density and maximum dielectric constant (ɛ<inf>m</inf>) decreased from 5.48 to 5.29 g/cm<sup>3</sup> and from 4667 to 2313, respectively, when x increased from 0 to 0.05. A decrease in the dielectric properties caused by the phase ratio shifting away from a morphotropic phase boundary (MPB) condition, poor microstructure and low density was produced with La<sup>3+</sup> replacement. The maximum polarization (P<inf>max</inf>), remnant polarization (P<inf>r</inf>) and coercive field (E<inf>c</inf>) decreased with increased La<sup>3+</sup> content. A decline in P<inf>r</inf> and E<inf>c</inf> improved the energy storage efficiency (ƞ) and energy storage loss (W<inf>loss</inf>), resulting in enhanced energy storage properties. At x = 0.02, the ceramic showed good energy storage properties (W<inf>total</inf> of 0.781 J/cm<sup>3</sup>, W<inf>rec</inf> of 0.624 J/cm<sup>3</sup>, W<inf>loss</inf> of 0.157 J/cm<sup>3</sup> and ƞ of 79.8%), measured at 60 kV/cm.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Phase structure, microstructure, electrical and energy storage properties of SBNLT lead free ceramics with Zr4+ substituted into B-sites
    (2024-09-01)
    Sinkruason, Thanapon
    ;
    Luangpangai, Anupong
    ;
    Julphunthong, Phongthorn
    ;
    Rittidech, Aurawan
    ;
    Pulphol, Phieraya
    Lead-free (Sr<inf>0.3</inf>Bi<inf>0.35</inf>Na<inf>0.335</inf>Li<inf>0.015</inf>) (Ti<inf>1−x</inf>Zr<inf>x</inf>) O<inf>3</inf> ceramics (SBNLT<inf>1−x</inf>Zr<inf>x</inf>) with x = 0–0.04 were prepared via the solid-state combustion technique using glycine as the fuel. The influence of Zr content on the phase structure, microstructure, electrical properties, and energy storage properties of the SBNLT<inf>1−x</inf>Zr<inf>x</inf> ceramics was examined. The presence of a pure perovskite phase was shown by X-ray diffraction (XRD) patterns, with the coexistence of rhombohedral and tetragonal phases in all samples, as certified by the Rietveld refinement method. Scanning electron microscopy (SEM) was utilized to observe the morphology of the SBNLT<inf>1−x</inf>Zr<inf>x</inf> ceramics, which revealed cube shaped grains with anisotropic growth. Average grain size increased from 2.01 to 2.49 µm when x increased from 0 to 0.01 and then reduced with further increases in Zr content. The maximum dielectric constant dropped from 4667 to 2990 when x increased from 0 to 0.04, caused by a shift from the morphotropic phase boundary (MPB). The maximum polarization (P<inf>max</inf>) of 29.18 µC/cm<sup>2</sup>, energy storage density (W<inf>total</inf>) of 0.851 J/cm<sup>3</sup> and recoverable energy storage (W<inf>rec</inf>) of 0.609 J/cm<sup>3</sup> were achieved when x = 0.02.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Effect of Na+ Substitution on the Phase, Microstructure, Electrical and Energy Storage Properties of BSBZNT Ceramics Prepared by the Solid-State Combustion Technique
    (2023-01-01)
    Chongsatan, Wistsarut
    ;
    Didpim, Ratirom
    ;
    Julphunthong, Phongthorn
    ;
    Thatawong, Bhoowadol
    ;
    Vittayakorn, Naratip
    (Ba<inf>0.704</inf>Sr<inf>0.176</inf>Bi<inf>0.12</inf>)<inf>1-x</inf>Zn<inf>0.08</inf>Nb<inf>0.04</inf>Ti<inf>0.88</inf>O<inf>3</inf>-Na<inf>x</inf> (BSBZNT-xNa) ceramics with x = 0, 0.01, 0.03 and 0.05 mol%, were prepared by the solid-state combustion technique. The samples were calcined and sintered at 950 °C and 1375 °C, respectively, for 2 h. The phase, microstructure, dielectric, ferroelectric and energy storage properties were investigated. The X-ray diffraction patterns of the BSBZNT-xNa powders showed a perovskite phase for all samples. When x increased from 0-0.03, the average particle size increased from 380 to 480 nm, then decreased to 420 nm. All sintered samples showed the coexistence of the orthorhombic and cubic phases. The average grain size was in the range of 2.03 to 1.39 µm. The BSBZNT-0.01Na ceramic exhibited the highest dielectric properties at room temperature (ɛ<inf>r</inf> = 902, tanδ = 0.10), the lowest remanent polarization (P <inf>r</inf> = 0.10 µC/cm<sup>2</sup>), coercive field (E <inf>c</inf> = 0.43 kV/cm), and the highest energy storage efficiency (η ∼ 94.70%) measured under an electric field of 70 kV/cm.