Vittayakorn, Naratip

Loading...
Thumbnail Image
Preferred name
Vittayakorn, Naratip
Alternative Name
Vittayakorn, N.
Vittayakorn, Narathip
Main Affiliation
Email
naratip.vi@kmitl.ac.th

Settings

Now showing 1 - 2 of 2
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Phase evolution, microstructure and electrical response of KNNT ceramics with Li+ substitution and doping
    (2022-01-01)
    Yotthuan, Surirat
    ;
    Udeye, Thanya
    ;
    Prasertpalichat, Sasiphon
    ;
    Pulphol, Phieraya
    ;
    Vittayakorn, Naratip
    Lead-free (K<inf>0.5</inf>Na<inf>0.5</inf>)(Nb<inf>0.7</inf>Ta<inf>0.3</inf>)O<inf>3</inf> (KNNT) ceramics with Li<sup>+</sup> substitution (KN<inf>0.5-x</inf>Li<inf>x</inf>NT) and direct (KNNT-xLi) doping at x = 0, 0.01, 0.02, 0.03 and 0.04 mol% were synthesized by the solid-state combustion route. The phase, microstructure, dielectric and ferroelectric properties of the ceramics were examined. The XRD pattern of the ceramics revealed orthorhombic and tetragonal phases in all specimens. The Rietveld refinement procedure showed that increasing either the Li<sup>+</sup> substitution or doping levels enhanced the amount of the tetragonal phase. It was found that Li<sup>+</sup> doping, either substitutional or additional, enhanced the Curie temperature (T <inf>C</inf>) by increasing the tetragonal distortion, while the dielectric constant (ε <inf>C</inf>) decreased. The good remanent P-E loops of the KN<inf>0.5-x</inf>Li<inf>x</inf>NT ceramics were found with x = 0.01 (P <inf>r</inf>∼10.89 µC/cm<sup>2</sup> and E <inf>C</inf>∼13.09 kV/cm), while for KNNT-xLi ceramics, it was obtained with x = 0.02 (P <inf>r</inf>∼15.65 µC/cm<sup>2</sup> and E <inf>C</inf>∼11.46 kV/cm), which were confirmed by remanent P-E hysteresis measurements.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    The influences of Cs+ substitution and direct doping on the phase evolution, microstructure and electrical properties of KNNT ceramics
    (2021-01-01)
    Yotthuan, Surirat
    ;
    Udeye, Thanya
    ;
    Vittayakorn, Naratip
    ;
    Eitssayeam, Sukum
    ;
    Pulphol, Phieraya
    The effects of Cs<sup>+</sup> substitution and direct doping in (K<inf>0.5</inf>Na<inf>0.5</inf>)(Nb<inf>0.7</inf>Ta<inf>0.3</inf>)O<inf>3</inf> (KNNT) ceramics, on the crystal structure, microstructure and electrical properties were investigated. Both the KNNT with Cs<sup>+</sup> substitution (K<inf>0.5-x</inf>Cs<inf>x</inf>NNT) and addition (KNNT-xCs) (x = 0, 0.01, 0.02, 0.03 and 0.04 mol%) were synthesized by the solid-state combustion technique using glycine as fuel. All samples were sintered at 1130–1150 °C for 4 h. The x-ray diffraction (XRD) analysis for the ceramics revealed the presence of orthorhombic (O) and tetragonal (T) phases in all samples. Increasing both the Cs<sup>+</sup> substitution and doping amounts, enhanced the content of orthorhombic phase, as verified by the Rietveld refinement technique. It was found that Cs<sup>+</sup> doping, either substitutional or additional, strongly decreased their density, dielectric and ferroelectric properties. The undoped KNNT ceramic exhibited well-saturated P-E hysteresis loop. With Cs<sup>+</sup> doping, the samples became unsaturated and a leakage current was produced. The KNNT-xCs ceramics demonstrated higher density and dielectric properties than the K<inf>0.5-x</inf>Cs<inf>x</inf>NNT ceramics.