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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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    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.
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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.