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Author: search.filters.author.Jantaratana, PongsakornSubject: search.filters.subject.Dielectric

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    Electric and magnetic properties of multiferroic CZFMO doped BNLTBKTBaT composite ceramics prepared via the solid-state combustion method
    (2025-07-01)
    Klinbanmor, Metarsit
    ;
    Thatawong, Bhoowadol
    ;
    Somsri, Widchaya
    ;
    Prasertpalichat, Sasiphon
    ;
    Vittayakorn, Naratip
    The present research work describes in detail investigations of the multiferroic properties of (1-x) (0.85Bi<inf>0.5</inf>Na<inf>0.475</inf>Li<inf>0.025</inf>TiO<inf>3</inf>-0.11Bi<inf>0.5</inf>K<inf>0.5</inf>TiO<inf>3</inf>-0.04BaTiO<inf>3</inf>)-xCo<inf>0.6</inf>Zn<inf>0.4</inf>Fe<inf>1.7</inf>Mn<inf>0.3</inf>O<inf>4</inf> [(1-x)BNLTBKTBaT-xCZFMO]; x = 0, 0.05, 0.10, 0.15 and 0.20 composite ceramics, synthesized by the solid-state combustion technique. The effect of increasing x content on the phase structure, microstructure, electrical and magnetic properties of (1-x)BNLTBKTBaT-xCZFMO composite ceramics was investigated. X-ray diffraction patterns of the BNLTBKTBaT sample showed a pure perovskite phase (rhombohedral and tetragonal structures). When CZFMO was added, the XRD patterns showed a co-structure between perovskite and cubic spinel ferrite structures. The composite grains were composed of large and small sizes, which were composed of mainly the elements of BNLTBKTBaT and CZFMO, respectively. As x increased, the average grain size of the larger grains increased, and the smaller grains got smaller. The density decreased from 5.54 to 4.61 g/cm<sup>3</sup> as x increased. Increasing the amount of CZFMO in BNLTBKTBaT also resulted in a decrease in the dielectric constant (ε<inf>r</inf>) and the remnant polarization (P<inf>r</inf>), with the leakage current observed at x = 0.20. The saturation magnetization (M<inf>s</inf>) and the magnetoelectric coupling coefficient (α<inf>E</inf>) increased with increased x. It was found that x = 0.15 gave the optimal electric, magnetic, and magnetoelectric properties (ε<inf>r</inf> = 425, P<inf>r</inf> = 1.64 μC/cm, M<inf>s</inf> = 1.1948 emu/g and α<inf>E</inf> = 4.88 mV/cm-Oe), which makes the composite potentially more applicable for information technology and spintronics devices.
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    ELECTRICAL AND MAGNETIC PROPERTIES OF MULTIFERROIC Co0.6Zn0.4Fe1.7Mn0.3O4 DOPED 0.99Bi0.47Na0.47Ba0.06TiO3-0.01Ba(Sn0.70Nb0.24)O3 CERAMICS SYNTHESIZED VIA THE SOLID-STATE COMBUSTION TECHNIQUE
    (2025-01-01)
    Luangpangai, Anupong
    ;
    Chuai, Phomphon
    ;
    Rittidech, Aurawan
    ;
    Pinitsoontorn, Supree
    ;
    Jantaratana, Pongsakorn
    Multiferroic (1-x)[0.99Bi<inf>0.47</inf>Na<inf>0.47</inf>Ba<inf>0.06</inf>TiO<inf>3</inf>-<inf>0.01</inf>Ba(Sn<inf>0.70</inf>Nb<inf>0.24</inf>)O<inf>3</inf>]-xCo<inf>0.6Z</inf>n<inf>0.4</inf>Fe<inf>1.7</inf>Mn<inf>0.3</inf>O<inf>4</inf> (abbreviated as BNBT-BSN-xCZFMO) ceramics with x ranging from 0 to 0.20 were fabricated using the solid-state combustion technique. The effect of varying BNBT-BSN: CZFMO ratios on the phase structure, microstructure, electrical and magnetic properties was investigated. X-ray diffraction (XRD) analysis of pure BNBT-BSN showed a perovskite structure with rhombohedral and tetragonal phases. The doped BNBT-BSN-xCZFMO ceramics displayed coexisting rhombohedral, tetragonal, and cubic spinel phases, with the cubic spinel phase increasing when the CZFMO content increased. In addition, the XRD peaks shifted to higher angles as the CZFMO content increased, indicating a decrease in lattice parameters. The dielectric constant decreased with higher CZFMO content and higher frequencies. The pure BNBT-BSN ceramic exhibited a saturated P-E loop with a Pmax of 33.2 µC/cm<sup>2</sup>, Pr of 26.1 µC/cm<sup>2</sup>, and an Ec of 14.5 kV/cm. With increased CZFMO content, non-saturated and bloated P-E loops with lower Pmax, Pr, and Ec were observed, implying a rise in the leakage current. The addition of CZFMO induced ferromagnetic behavior in the ceramics, leading to an increase in Ms and a reduction in Hc as CZFMO content increased. The magnetoelectric coupling coefficient of BNBT-BSN-xCZFMO ceramics continuously increased with higher CZFMO content.
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    ELECTRIC AND MAGNETIC PROPERTIES OF Ni0.475Zn0.475Li0.025Al0.025Fe2O4 DOPED (Bi0.5Na0.5)0.94Ba0.06TiO3 CERAMICS PREPARED BY THE SOLID-STATE COMBUSTION METHOD
    (2025-01-01)
    Pattanakasem, Wiwat
    ;
    Sookboon, Chirarat
    ;
    Somsri, Widchaya
    ;
    Vittayakorn, Naratip
    ;
    Pinitsoontorn, Supree
    In this study, we synthesized (1-x)((Bi<inf>0.5</inf>Na<inf>0.5</inf>)<inf>0.94</inf>Ba<inf>0.06</inf>TiO<inf>3</inf>)-x Ni<inf>0.475</inf>Zn<inf>0.475</inf>Li<inf>0.025</inf>Al<inf>0.025</inf>Fe<inf>2</inf>O<inf>4</inf> [(1-x)BNBT-xNZLAF] ceramics with x= 0, 0.05, 0.10, 0.15, and 0.20 using the solid-state combustion method. The phase formation, microstructure, and dielectric, ferroelectric, ferromagnetic, and magnetoelectric properties were investigated. BNBT and NZLAF powders were calcined at 750°C and 900°C for 2 h., respectively. The calcined powders were then mixed in various ratios to produce (1-x)BNBT-xNZLAF composites, which were sintered at 1125°C for 2 h. X-ray diffraction analysis indicated that undoped BNBT ceramics exhibited a typical perovskite structure with coexisting rhombohedral (R) and tetragonal (T) phases. With increasing NZLAF content, the cubic spinel (C) phase emerged with the R and T perovskite phases. Rietveld refinement indicated a higher percentage of the C phase as x increased. When x increased from 0 to 0.10, the average grain size and density increased (from 1.0 to 9.8 m and 5.45 to 5.61 g/cm3, respectively) followed by a drop at higher NZLAF levels. Doping BNBT ceramics with NZLAF resulted in a reduction in the dielectric constant (εr), dielectric loss (tan δ), and remnant polarization (Pr). The undoped BNBT ceramic showed a saturated P-E hysteresis loop, while NZLAF doped ceramics exhibited unsaturated P-E loops and increased leakage current. Magnetic measurements showed a transition from diamagnetic to ferromagnetic behavior with NZLAF doping. As x increased, the remnant magnetization (Mr), saturation magnetization (Ms), and magnetoelectric coefficient also increased (Mr0.058 emu/g, Ms3.594 emu/g, and MEcoefficient 2.64 mV/cm•Oe at x=0.25). These results suggest that NZLAF-doped BNBT ceramics hold potential for multiferroic material applications.