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Multifunctional properties of Mn and Fe co-doped lead-free BCT perovskite ceramics synthesized via solid-state combustion
(2025-10-01)
Kornphom, Chittakorn
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Sonchaopri, Nutkamon
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Yimsabai, Sununta
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Jantaratana, Pongsakorn
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Pinitsoontorn, Supree
There is a growing demand to improve the performance of multiferroic lead-free ceramics. Good ferroelectric and magnetic properties are key parameters for achieving high magnetoelectric coupling (ME). In this work, Mn and Fe were co-doped into lead-free Ba<inf>0.96</inf>Ca<inf>0.04</inf>Ti<inf>(1-x)</inf>(Mn<inf>0.5</inf>Fe<inf>0.5</inf>)<inf>x</inf>O<inf>3</inf> (BCT-xMF) ceramics with 0 ≤ x ≤ 0.030 mol%, synthesized by the solid-state combustion technique. X-ray diffraction (XRD) analysis and Rietveld refinement confirmed the formation of a pure phase with coexisting tetragonal and cubic phases in all compositions. As the Mn/Fe content increased, the percentage of the tetragonal phase decreased while the cubic phase increased, consistent with Raman spectroscopy results. Increasing Mn/Fe content also led to more oxygen vacancies and defects, and a decrease in average grain size. Analysis of the temperature-dependent dielectric constant revealed a reduction in the Curie temperature from 116 to 67 °C, corresponding to the tetragonal-to-cubic phase transformation. The ceramic with x = 0.015 showed the highest dielectric constant at the Curie temperature (ε<inf>c</inf>), maximum saturated polarization (P<inf>s</inf>), remnant polarization (P<inf>r</inf>), saturation magnetization (M<inf>s</inf>), and remnant magnetization (M<inf>r</inf>), with values of 4583, 14.09 μC/cm2, 9.31 μC/cm2, 0.0127 emu/g, and 0.006 emu/g, respectively. These results indicate that Fe/Mn co-doping into BCT ceramics enhanced both ferroelectric and ferromagnetic properties, resulting in a high magnetoelectric coefficient (α<inf>ME</inf>∼1.27 mV/cm Oe) at room temperature, making these ceramics candidates for multiferroic applications.
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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
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Somsri, Widchaya
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Vittayakorn, Naratip
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Charoenthai, Nipaphat
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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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Enhanced electrical and energy storage performances of Fe, Sb co-doped BNBCTS ceramics synthesized via the solid-state combustion technique
(2024-12-01)
Kornphom, C.
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Saenkam, K.
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Yotthuan, S.
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Vittayakorn, N.
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Bongkarn, T.
In this study BNBCTS ceramics were co-doped with Fe and Sb to form (Bi<inf>0.5</inf>Na<inf>0.5</inf>)<inf>0.93</inf>(Ba<inf>0.945</inf>Ca<inf>0.055</inf>)<inf>0.07</inf>(Ti<inf>(0.9946-x)</inf>Sn<inf>0.0054</inf>)(Fe<inf>0.5</inf>Sb<inf>0.5</inf>)<inf>x</inf>O<inf>3</inf> ceramics (denoted as BNBCTS-xFS) with various x content and were prepared via the solid-state combustion technique to enhance the electrical and energy storage performance. The effect of co-doping Fe and Sb on the phase formation, defect dipole, microstructure, electrical and energy storage properties of BNBCTS-xFS ceramics was studied. When x content increased from 0.0 to 0.030, the amount of the rhombohedral (R) phase decreased from 51 to 24 % while the tetragonal (T) phase increased from 49 to 76 %. The increased Fe and Sb content increased the defect dipole of singly/doubly charged oxygen-vacancies (V<inf>O</inf>∙/ V<inf>O</inf>∙∙) and caused more Ti4+ to transition to Ti3+, which caused the transition temperature of the ferroelectric phase to relaxor state (T<inf>F-R</inf>) in the ceramics to drop to below room temperature and it exhibited relaxor characteristics at room temperature. The ceramic with an x content of 0.010 had the largest grain size (3.06 μm), excellence ferroelectric properties (P<inf>r</inf> ∼31.04 μC/cm2, P<inf>m</inf> ∼38.98 μC/cm2 and E<inf>c</inf> ∼18.28 kV/cm), the largest electro strain (∼0.175 %) and a large d<inf>33</inf>* of 350 pm/V. Moreover, when x = 0.020, the ergodic relaxor ceramic showed the smallest grain size (1.03 μm), the lowest remanant polarization (P<inf>r</inf>) of 4.52 μC/cm2 and the lowest coercive field (E<inf>c</inf>) of 8.37 kV/cm, at an electric field of 60 kV/cm. More importantly, energy storage properties at the electric breakdown strength (E<inf>b</inf> = 120 kV/cm) of the ceramics with an x content of 0.020 exhibited a recoverable energy storage density (W<inf>rec</inf>) of 1.81 J/cm3, a total energy storage density (W<inf>total</inf>) of 2.95 J/cm3 and an efficiency (η) of 61.30%, with excellent thermal (∼25–150 °C) and frequency stability (∼1–100 Hz). This study provides new insights into the modulation of BNBCTS ceramics with Fe and Sb co-doping, which could effectively improve the electrical properties and energy storage properties of BNBCTS-xFS ceramics.
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Phase Formation, Microstructure and Electric Properties of Vanadium Doped Lead-Free BaTi0.91Sn0.09O3 Ceramics
(2023-01-01)
Pattanakasem, Wiwat
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Charoenthai, Nipaphat
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Vittayakorn, Naratip
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Bongkarn, Theerachai
Lead-free Ba(Ti<inf>0.91</inf>Sn<inf>0.09</inf>)<inf>1-x</inf>V<inf>x</inf>O<inf>3</inf> (BTSV, x = 0, 0.005,0.010, 0.015, and 0.020) ceramics were prepared by the conventional solid-state sintering method with a calcination temperature of 1200 °C for 2 h and a sintering temperature between 1350 °C and 1400 °C for 4 h. The effect of vanadium (V) doping on the phase formation, microstructure and electrical properties of the ceramics was investigated. X-ray diffraction (XRD) measurements revealed that the ceramics with x = 0 and 0.005 had pure perovskite structures with no detectable impurity, while the ceramics with x ≥ 0.010 exhibited perovskite structures and had secondary impurity phases. Coexisting orthorhombic and tetragonal phases were observed and the Rietveld refinement analysis suggested that the tetragonal phase increased with increased V5+ substitution. When x increased from 0 to 0.010, the average grain size increased from 47 to 62 µm and then dropped, while the density (ρ) decreased from 5.98 to 5.64 g/cm3 when x increased. Furthermore, the BTSV ceramics exhibited increased porosity, Curie temperatures (T <inf>C</inf> ∼ 42 °C to 52 °C) and coercive field (E <inf>c</inf>), while the dielectric constant at the Curie temperature (ε<inf>C</inf>) and the remnant polarization (P <inf>r</inf>) of the ceramics decreased (∼18023 to 6110 and ∼7.42 to 4.88 µC/cm2, respectively) when V5+ doping increased.
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The correlation between phase formation and the structure of the pellets with the fungal immobilization study as a commercial substrate culture/planting material
(2022-01-01)
Sumang, Rattiphorn
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Kodsueb, Rampai
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Vitayakorn, Narathip
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Chutima, Ruangwut
Calcined clay pellets are popular planting material for those who love to grow plants in pots. The calcined clay pellets consist of clay (C), phosphate rock (PR), and rice husk ash (RHA). [(1-x)(50C–50PR)-xRHA], x(RHA) = 0, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, and 0.65 wt% were prepared by a conventional solid-state reaction method. The samples were made into a spherical shape with a diameter of 10 mm and fired at 600℃ to 1000℃. The effect of x contents on phase formation, microstructure, and chemical properties of [(1-x)(50C–50PR)-xRHA] was studied. X-ray diffraction revealed the typical assemblages with quartz, illite, and kaolinite in all the samples. SEM images of samples showed irregular packing and a highly porous microstructure. The addition of x(RHA) contents results in porous microstructure in all the samples. The surface area and pore volume of samples increased from 8.83 m2·g-1 to 14.71 m2·g-1 and 0.938 cm3·g-1 to 0.942 cm3·g-1, respectively, with the increase of x(RHA). The density of the samples slightly decreased from 2.45±0.06 g·cm-3 to 1.94±0.05 g·cm-3, with an increase in x(RHA) contents. The capability of calcined clay pellets to immobilize plant growth-promoting fungi was then studied. The results showed that orchid endophytes, as plant growth-promoting fungi, grow well on the calcined clay pellets saturated with potato dextrose broth (PDB). Besides, all fungi can live on calcined clay pellets and stay viable for at least 35 days after inoculation. These results suggested that the calcined clay pellets could serve as planting material that enhances plant growth (via its nutrients and growth-promoting fungi) simultaneously.
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Effect of sr substitution on structural, ferroelectric and magnetic properties of la1-xsrxfeo3 perovskite oxides
(2020-01-01)
Kaewpanha, Malinee
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Nunocha, Pornnipa
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Bongkarn, Theerachai
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Eiad-Ua, Apiluck
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Suriwong, Tawat
Effect of Sr substitution on structural, magnetic and electrical properties of LaFeO<inf>3</inf> perovskite oxides has been studied. Using the selected Sr doping content (x) from 0.0 to 1.0, perovskite La<inf>1-x</inf>Sr<inf>x</inf>FeO<inf>3</inf> nanopowder was synthesized by sol-gel auto-combustion method, followed by calcination at 900 °C for 2 h. The synthesized powder was pressed into disks at room temperature and then the disk samples were sintered at 1200 °C for 12 h to obtain a single-phase compound formation and uniaxial compaction. The influence of Sr doping on the phase formation, morphology, ferroelectric and magnetic properties was investigated. The phase formation of the sample changes from orthorhombic at low Sr doping through rhombohedral to cubic for Sr-rich sample as the stoichiometry approached SrFeO<inf>3</inf>. The grains of La<inf>1-x</inf>Sr<inf>x</inf>FeO<inf>3</inf> ceramics revealed an irregular polyhedron shape. SEM-EDS mapping analysis also exhibited the uniform distribution of all elements. The direct energy gap (E<inf>g</inf>) was found to decrease with increasing amounts of Sr doping. Moreover, the La<inf>0.6</inf>Sr<inf>0.4</inf>FeO<inf>3</inf> ceramic exhibited ferromagnetic behavior with saturated magnetization (M<inf>s</inf>) of 0.305 emu/g at room temperature.
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Phase formation and evolution of Cu:Zn partials in binary metal pyrophosphates Cu(2-x)Zn(x)P2O7; X ≈ 1
(2014-11-20)
Baitahe, Rattanai
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Vittayakorn, Naratip
Binary metal pyrophosphate powders were prepared by the solid state reaction method and subsequently calcined at 400, 500, 600, 700, and 800 °C in order to study Cu:Zn partial evolution to the final CuZnP<inf>2</inf>O<inf>7</inf> product. Synchrotron X-ray absorption, X-ray diffraction, Raman, FT-IR spectroscopy, and thermogravimetric analysis were used in this investigation. Phase evolution of the reaction products was investigated systemically. The results showed that complicated mixtures contributed to the reaction of synthesis temperature. The reaction comprised 3CuO·2P<inf>2</inf>O<inf>5</inf>·0.3NH<inf>3</inf>·0.2H<inf>2</inf>O, Cu<inf>2</inf>P<inf>2</inf>O<inf>7</inf>, Zn<inf>2</inf>P<inf>2</inf>O<inf>7</inf>, and Zn<inf>2</inf>P<inf>2</inf>O<inf>7</inf>·3H<inf>2</inf>O intermediates. Decreasing percentage of 3CuO·2P<inf>2</inf>O<inf>5</inf>·0.3NH<inf>3</inf>·0.2H<inf>2</inf>O intermediates was related directly to an increasing final product. Cu:Zn contents changed in Cu<inf>(2-x)</inf>Zn<inf>(x)</inf>P<inf>2</inf>O<inf>7</inf> in the temperature range of 400-600 °C, when x ≈ 1 clearly was related linearly to the reaction temperature. The final product was confirmed by EXAFS fitting spectra as solid solution between the Cu and Zn atom in the CuZnP<inf>2</inf>O<inf>7</inf> structure, and it indicated environment around metal atoms.
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Use of the combustion technique for the preparation of Ba(Ti 0.70Zr0.30)O3 ceramics
(2010-12-01)
Phungjitt, N.
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Panya, P.
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Vittayakorn, N.
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Bongkarn, T.
The preparation conditions for barium titanate zirconate [Ba(Ti <inf>0.70</inf>Zr<inf>0.30</inf>)O<inf>3</inf>] ceramics by the combustion method were studied. The X-ray diffraction pattern indicated that the calcined powders belonged to a cubic phase. The maximum percentage of the cubic perovskite phase was found in the sample calcined at 850°C. A pure cubic crystal structure was found in all ceramic samples. The average grain size increased with increasing sintering temperatures. The dielectric constant-temperature plots showed a maximum peak value of 5800 from ceramic sintered at 1350°C. The densities of samples corresponded to the dielectric constant. A diffuse phase transition was also observed.
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Effect of firing temperatures on phase formation and microstructure of Ba(Zr0.3Ti0.7)O3 ceramics prepared via mixed oxide method
(2009-12-01)
Bongkarn, Theerachai
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Phungjitt, Nalinee
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Vittayakorn, Naratip
Ba(Zr0.3Ti0.7)O3 (BZT) ceramics were fabricated by a mixed oxide synthetic route. The effect of calcination and sintering temperatures on phase formation and the microstructure of the ceramics were investigated. The pure perovskite phase of BZT powders was obtained with a calcination condition of 1300°C for 4 h. The sintered pellets showed a pure peroverskite cubic phase in all samples. The microstructure of the powders exhibited an almost-spherical morphology and had a porous agglomerated form. The average particle sizes and the average grain sizes were increased from 0.2 to 1.1 μm and 3.9 to 25.1 μm with increasing calcination and sintering temperatures, respectively. The densest and the highest maximum dielectric constant was found in the BZT ceramic sintered at 1550°C. Copyright © Taylor & Francis Group, LLC.
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Effect of calcination temperatures on microstructure and phase formation of Ba(Zr0.25Ti0.75)O3 powders
(2008-12-01)
Bongkarn, T.
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Phungjitt, N.
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Vittayakorn, N.
In this work, the effect of calcination temperatures on the microstructure and phase formation of Ba(Zr<inf>0.25</inf>Ti<inf>0.75</inf>)O<inf>3</inf> (BZT) powders were investigated. The BZT powders were prepared via the solid state reaction method under various calcination temperatures. It was found that the second phases such as BaCO<inf>3</inf> ZrO<inf>2</inf>, BaZrO<inf>3</inf> and Ba<inf>2</inf>ZrO<inf>4</inf> existed in samples with calcination temperature below 1200 °C. Homogeneity and a highly pure perovskite phase of the BZT powders were obtained with calcination condition at 1300 °C for 4 h. Lattice parameter a and the percentage of cubic perovskite phase tended to increase with increasing calcination temperatures. The TG-DTA results corresponded to the XRD investigation. The microstructures of calcined powders exhibited an almost-spherical morphology and had a porous agglomerated form in all samples. The average particle sizes were increased from 0.2 to 1.1 μm when calcination temperatures were increased from 800 to 1350 °C. © 2008 Trans Tech Publications, Switzerland.

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