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    PHASE FORMATION AND ELECTRICAL PROPERTIES OF BCLTS CERAMICS SYNTHESIZED VIA THE SOLID-STATE COMBUSTION TECHNIQUE
    (2025-01-01)
    Somsri, Widchaya
    ;
    Charoenthai, Nipaphat
    ;
    Sutthapintu, Aekkasit
    ;
    Noisak, Jitrawan
    ;
    Vittayakorn, Naratip
    Lead-free Ba<inf>0.93</inf>Ca<inf>0.04</inf>La<inf>0.03</inf>Ti<inf>0.90</inf>Sn<inf>0.10</inf>O<inf>3</inf> (BCLTS) ceramics were fabricated via solid-state combustion technique. The BCLTS powders were calcined in a temperature range of 1075-1175°C for 2h and sintered in a temperature range of 1350-1450°C for 2h. The BCLTS powders exhibited a pure perovskite phase when calcined above 1150°C. All BCLTS ceramic samples displayed a perovskite structure with coexisting cubic and tetragonal phases, with a secondary phase observed only at 1450°C. The growth of grain size was increased with increasing sintering temperature (0.42 to 0.65 μm.). The highest dielectric and ferroelectric properties (ε<inf>r</inf>=3047, tan δ<inf>r</inf> = 0.029, P<inf>max</inf> = 9.52 μC/cm<sup>2</sup>, P<inf>r</inf> = 0.48 μC/cm<sup>2</sup>, E<inf>c</inf>= 1.04 kV/cm) were obtained at the sintering temperature of 1400°C. The altered phase structure in this research, compared to earlier studies, results in distinct outcomes for the dielectric and ferroelectric properties.
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    EFFECT OF FIRING TEMPERATURE ON THE PHASE FORMATION, MICROSTRUCTURE, AND ELECTRICAL PROPERTIES OF BST-BZN CERAMICS
    (2025-01-01)
    Somsri, Widchaya
    ;
    Duangkeaw, Panadda
    ;
    Sumang, Rattiphorn
    ;
    Pulphol, Phieraya
    ;
    Vittayakorn, Naratip
    Lead-free 0.88Ba0.8Sr0.2TiO3-0.12Bi(Zn2/3Nb1/3)O3 (BST-BZN) ceramics were prepared by the solid-state combustion technique, using glycine as fuel. The BST-BZN ceramics were calcined between 900–1100°C for 2 h and sintered between 1300–1400°C for 2 h. A pure perovskite phase with a pseudo-cubic structure was observed by XRD and confirmed by the Rietveld refinement technique. The average particle and grain sizes tended to increase with increased calcination and sintering temperatures. The measured density was in the range of 5.65–5.90 g/cm<sup>3</sup>. The dielectric constant (εr) and dielectric loss (tan δr) decreased with increased sintering temperatures, up to 1350°C and then increased. The energy storage density (Wtotal) and energy storage efficiency (η) of the ceramics were 0.488 J/cm<sup>3</sup> and 94.1% measured at 100 kV/cm, respectively, obtained by the sample sintered at 1375°C
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    PHASE FORMATION AND ELECTRICAL PROPERTIES OF Ba0.91Ca0.09Ti0.916Sn0.084O3-0.1WT%ZnO -0.1WT%MnO2 LEAD-FREE FERROELECTRIC CERAMICS SYNTHESIZED VIA THE SOLID-STATE COMBUSTION METHOD
    (2025-01-01)
    Yimsabai, Sununta
    ;
    Somsri, Widchaya
    ;
    Vittayakorn, Naratip
    ;
    Charoenthai, Nipaphat
    ;
    Suthapintu, Aekasit
    This work investigated the effect of firing temperatures on the phase formation, microstructure, and electrical properties of Ba0.91Ca0.09Ti0.916Sn0.084O3-0.1wt%ZnO-0.1wt%MnO2 (BCTS-ZnMn) lead-free ferroelectric ceramics synthesized via the solid-state combustion method. Glycine was used as fuel to reduce the synthesis temperature. The samples were calcined at temperatures from 1050 to 1250°C (in 50°C increments) for 3 h and sintered from 1250 to 1450°C (in 50°C increments) for 3 h. A pure perovskite phase was found in the powders calcined above 1100°C. The phase structure, microstructure, dielectric and ferroelectric properties of the ceramics were examined. The X-ray diffraction (XRD) analysis for the ceramics revealed the presence of tetragonal (T) and orthorhombic (O) phases in all the ceramics. The average particle size and average grain size increased with increasing firing temperatures. The density, dielectric constant at the Curie temperature (ɛc), Pr and Ps tended to increase with increasing sintering temperatures, up to 1400°C, and then decreased at 1450°C. The ceramic sintered at 1400°C exhibited the highest density (5.89 g/cm3), dielectric response (ɛc = 13324) and good ferroelectric behavior (Pr = 8.67 μC/cm2, Ps = 17.92 μC/cm2 and Ec = 0.99 kV/cm).
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    Phase formation, electric and magnetic properties of multiferroic 0.7Ba0.9Ca0.1TiO3-0.3Ni0.6Zn0.4Fe2O4 composites ceramics synthesized by the solid-state combustion technique
    (2025-01-01)
    Sonchaopri, Nutkamon
    ;
    Somsri, Widchaya
    ;
    Chootin, Suphornphun
    ;
    Vittayakorn, Naratip
    ;
    Pinitsoontorn, Supree
    Multiferroic composite materials have both ferroelectric and ferromagnetic properties. In addition, the electrical and magnetic properties of these ceramics are primarily affected by the preparation temperature. Therefore, this study investigates the effect of the sintering temperature on the phase structure, microstructure, electrical and magnetic properties of multiferroic 0.7Ba<inf>0.9</inf>Ca<inf>0.1</inf>TiO<inf>3</inf>-0.3Ni<inf>0.6</inf>Zn<inf>0.4</inf>Fe<inf>2</inf>O<inf>4</inf> (BCT-NZF) composite ceramics synthesized by the solid-state combustion technique. The samples were sintered in a range of 1250–1350 ºC for 2 h. The X-ray diffraction (XRD) analysis revealed that all ceramics exhibited coexisting phases, with tetragonal perovskite, orthorhombic perovskite and cubic spinel phases, suggesting a complex crystalline structure. The average grain size of the ferroelectric and ferrite grains increased from 0.59 to 1.41 µm and 0.67 to 3.13 µm, respectively, moreover, ε and tanδ at 1 MHz tended to increase from 257.4 to 572.3 and 0.05 to 0.24, respectively, with increased sintering temperature. Density and saturated magnetization (M<inf>s</inf>) increased from 5.36 to 5.45 g/cm<sup>3</sup> and 19.36 to 20.38 emu/g, respectively, while remanent magnetization (M<inf>r</inf>) and coercivity (H<inf>d</inf><inf>c</inf>) decreased from 0.38 to 0.33 emu/g and 25.03 to 20.17 Oe, respectively, when the sintering temperature was increased from 1250 to 1300 °C. Above 1300 °C, the density and M<inf>s</inf> decreased, while M<inf>r</inf> and H<inf>d</inf><inf>c</inf> increased. With the optimum sintering temperature of 1300 °C, the multiferroic BCT-NZF composite ceramics exhibited the highest density (5.45 g/cm<sup>3</sup>), low leakage P-E loop, good magnetic properties (M<inf>s</inf> = 20.38 emu/g) and high magnetoelectric coupling (α<inf>ME</inf> = 4.03 mV/cm•Oe), indicating this ceramic was suitable for application in magnetoelectric devices.