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Structure–property correlations and magnetoelectric response of lead-free BNT–BCTS/CZFMO composite ceramics
(2026-06-01)
Kornphom, Chittakorn
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Sonchaopri, Nutkamon
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Yimsabai, Sununta
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Yotthuan, Surirat
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Jantaratana, Pongsakorn
Lead-free multiferroic composite ceramics have garnered increasing attention as an eco-friendly alternative for magnetoelectric (ME) devices. In this work, (100-x) [0.93(Bi<inf>0.5</inf>Na<inf>0.5</inf>TiO<inf>3</inf>) 0.07(Ba<inf>0.945</inf>Ca<inf>0.055</inf>Ti<inf>0.91</inf>Sn<inf>0.09</inf>O<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> composite ceramics, abbreviated as (100-x) BNT-BCTS/xCZFMO were synthesized via a solid-state combustion route. Analysis of XRD data using the Rietveld method confirmed the coexistence of rhombohedral and tetragonal perovskite (BNT–BCTS) phases and a cubic spinel (CZFMO) phase without additional impurity phases. The 0–3 connectivity was verified using SEM/EDS, PFM, and MFM measurements, confirming discrete CZFMO magnetic grains are embedded within a continuous BNT–BCTS piezoelectric matrix. Williamson–Hall (W–H) analysis, treated as a semi-quantitative approach due to fitting limitations in the multiphase composite system, suggested a composition-dependent microstrain trend. The reduced microstrain at intermediate CZFMO contents was consistent with enhanced crystallite growth, improved densification, and the maximum magnetoelectric response. The composition with x = 20 exhibits the highest relative density (~ 98.14%), the highest saturation magnetization (M<inf>s</inf> = 6.55 emu/g), and the maximum magnetoelectric coefficient (α<inf>ME</inf> = 7.92 mV cm−1 Oe−1), showing higher ME coefficients than many previously reported lead-free composites. This work demonstrates the potential of BNT–BCTS/CZFMO composites for multifunctional electronic devices, including magnetic sensors, energy harvesters, and magnetoelectric transducers.
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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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Improved Dielectric, Magnetic, and Multiferroic Properties of (Bi0.5Na0.5)0.7La0.3(Ti0.7Fe0.3)O3 Ceramics Synthesis by the Solid-State Combustion Technique
(2025-06-01)
Kornphom, Chittakorn
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Somsri, Widchaya
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Prasertpalichat, Sasipohn
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Thatawong, Bhoowadol
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Kruea-In, Chatchai
Lead-free (Bi<inf>0.5</inf>Na<inf>0.5</inf>)<inf>0.7</inf>La<inf>0.3</inf>(Ti<inf>0.7</inf>Fe<inf>0.3</inf>)O<inf>3</inf> ceramics (abbreviated as BNLTF) are synthesized by the solid-state combustion technique using glycine as fuel. The effect of the firing temperature (calcined between 700 and 800 °C for 2 h and sintered between at 800 and 900 °C for 2 h) on the phase structure, microstructure, electrical, and magnetic properties is investigated. Pure BNLTF powders are obtained with a calcination temperature of 750 °C for 2 h and the crystal size increases from 47 to 62 nm when the calcination temperature increases from 700 to 800 °C. All sintered BNLTF ceramics show a pure perovskite structure with a rhombohedral phase. The average grain size increases with increasing sintering temperatures. A well-packed microstructure with the highest density (5.98 g cm−3), good dielectric properties at room temperature (ε<inf>r</inf> ≈ 589 and tanδ ≈ 0.572), soft ferroelectric behavior, and excellent magnetic properties (M<inf>s</inf> ≈ 0.091 emu g−1, M<inf>r</inf> ≈ 0.0026 emu g−1) is obtained from the ceramic sintered at 875 °C for 2 h. The multiferroic BNLTF ceramic sintered at 875 °C has a maximum magnetoelectric coupling coefficient (α<inf>E</inf> ≈ 2.08 mV cm−1 Oe−1) when the magnetic field is near 4500 Oe.
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Sintering Temperature Effect on Phase Formation, Microstructure and Electrical Properties of Modified KNLNTS Solid Solution Prepared via the Solid-State Combustion Technique
(2023-01-01)
Kornphom, Chittakorn
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Thawong, Pichittra
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Khiwoon, Suprakorn
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Vittayakorn, Naratip
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Bongkarn, Theerachai
In this study, the effect of sintering temperature (1000–1100 °C for 2 h) on phase formation, phase transition, microstructure and electrical properties of lead-free piezoelectric (K<inf>0.44</inf>Na<inf>0.52</inf>Li<inf>0.04</inf>)(Nb<inf>0.84</inf>Ta<inf>0.10</inf>Sb<inf>0.06</inf>)O<inf>3</inf> (KNLNTS) solid solution with 0.3 wt%Bi<inf>2</inf>O<inf>3</inf> + 0.4 wt%Fe<inf>2</inf>O<inf>3</inf> + 0.2 wt%CuO additive (abbreviate as modified KNLNTS) was investigated. Modified KNLNTS ceramics were synthesized by the solid-state combustion technique using glycine as fuel. The modified KNLNTS powders were prepared using the calcination condition of 650 °C for 2 h. The XRD pattern of all sintered ceramics exhibited a pure perovskite phase. Using Rietveld refinement to analyze the phase formation showed that the modified KNLNTS ceramics had co-existing phases of orthorhombic and tetragonal in all sintered ceramics and the orthorhombic phase increased when the sintering temperature increased. The average grain size, T<inf>O-T</inf>, T<inf>c</inf>, P<inf>r</inf> and Ec increased with increasing sintering temperature. At the sintering temperature of 1025 °C, the modified KNLNTS ceramic showed the best electrical properties (C<inf>ε</inf> ≈ 6745, S<inf>max</inf> ≈0.274% and d*<inf>33</inf> ≈ 548 pm/V). The good electrical properties of the modified KNLNTS ceramics makes them good candidates for lead-free applications to replace Pb-based ceramics.
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Lead-free piezoelectric ceramics based on (1 − x)BNKLLT–xBCTZ binary solid solutions synthesized by the solid-state combustion technique
(2016-04-01)
Kornphom, Chittakorn
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Vittayakorn, Naratip
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Bongkarn, Theerachai
The aim of this work is to improve the electrical properties of BNKLLT ceramics with the addition of BCTZ. New binary (1 − x)BNKLLT-xBCTZ lead-free piezoelectric ceramics with different x contents between 0 and 0.10 (step 0.02) were fabricated by the solid-state combustion technique, where glycine was used as a fuel. The influences of x concentration on the phase evolution, morphology, and electrical behavior were investigated. The phase formation exhibited a coexistence of rhombohedral and tetragonal phases in all samples. With the increasing x content, the phase formation was dominated by a higher tetragonality. The average gain size continuously reduced from 1.52 to 0.96 µm when x content was increased. The maximum dielectric temperature (T<inf>SA</inf>) of these ceramics decreased with the increasing x content. The ferroelectric properties were further weakened with the increasing x content. The MPB region was obtained at x content of around 0.04 producing this sample and showed the highest dielectric constants (ε<inf>r</inf> = 2720 and ε<inf>SA</inf> = 6110) and an excellent piezoelectric constant (d<inf>33</inf> = 295 pC/N).
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Low firing temperatures and high ferroelectric properties of (Ba0.85Ca0.15)(Ti 0.90Zr0.10)O3 lead-free ceramics synthesized by the combustion technique
(2016-01-26)
Kornphom, Chittakorn
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Vittayakorn, Naratip
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Bongkarn, Theerachai
This work studied the effect of firing conditions on phase formation, microstructure and electrical properties of (Ba<inf>0.85</inf>Ca<inf>0.15</inf>)(Ti<inf>0.90</inf>Zr<inf>0.10</inf>)O<inf>3</inf>;(abbreviated as BCTZ) ceramics, which were synthesized through the combustion technique. To reduce the reaction temperature, glycine was used as fuel with a ratio of raw material: glycine (1:1.11). BCTZ samples were calcined at 900-1200°C for 2 h and sintered at 1350 -1550°C for 2 h. Ultrafine BCTZ powder and single peroveskite phase were achieved from the sample calcined at 1050°C for 2 h.These results were obtained at a lower temperature and with shorter dwell time than those obtained using the solid state reaction method by ∼150°C and 1 h, respectively. The BCTZ ceramics exhibited a coexistence of rhombohedral and orthorhombic phase in all samples. The average particle size and the average grain size increased from 172 to 295 nm and 0.82 to 2.57 μm, respectively, when firing temperatures increased. The highest density (5.76 g/cm3), highest dielectric constant (ε<inf>r</inf> ≅ 4485 and ε<inf>max</inf> ≅ 14897) and best ferroelectric properties (P<inf>r</inf> ≅ 18.47 C/cm2 and E<inf>C</inf> ≅ 4.52 kV/cm) were obtained from the sample sintered at 1450°C for 2 h.
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Structural, microstructure and electrical properties of La2O3-doped Bi0.5(Na0.68K0.22Li0.1)0.5TiO3 lead-free piezoelectric ceramics synthesized by the combustion technique
(2015-07-01)
Bhupaijit, Pamornnarumol
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Kornphom, Chittakorn
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Vittayakorn, Naratip
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Bongkarn, Theerachai
The effect of firing temperatures on phase formation, microstructure and physical properties of [Bi<inf>0.5</inf>(Na<inf>0.68</inf>K<inf>0.22</inf>Li<inf>0.1</inf>)<inf>0.5</inf>TiO<inf>3</inf>] doped with La<inf>2</inf>O<inf>3</inf> at 0.1 wt% (BNKLLT) ceramics prepared by the combustion method was studied. Glycine was used as fuel and the ratio of raw material (corresponding oxidant metal nitrate) with fuel was about 1:0.56. The samples were calcined at 600-900 °C for 2 h and sintered at 1075-1150 °C for 2 h. The single rhombohedral peroveskite phase of BNKLLT powders was observed from the sample calcined at 750 °C for 2 h. The BNKLLT ceramics exhibited a pure peroveskite phase in all samples. The microstructures of the BNKLLT powders exhibited an agglomerated form while the grain ceramics exhibited a square shape. The average particle size and average grain size increased with increasing firing temperatures. The density, dielectric constant (ε<inf>r</inf> and ε<inf>m</inf>), P<inf>r</inf> and d<inf>33</inf> tended to increase with increasing sintering temperatures up to 1100 °C and then decreased. The maximum density (5.73 g/cm2), maximum dielectric constant (ε<inf>r</inf>~2572 and ε<inf>m</inf>~5536), good ferroelectric properties (P<inf>r</inf>~35.78 μC/cm2 and E<inf>c</inf>~22.42 kV/cm) and highest d<inf>33</inf> (210 pC/N) were obtained by the sample sintered at 1100 °C for 2 h.
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Fabrication of 0.62[0.75PMN-0.25PYbN]-0.38PT ceramics using one step calcination via combustion technique
(2013-01-01)
Kornphom, Chittakorn
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Bhupaijit, Pamornnarumol
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Vittayakorn, Naratip
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Bongkarn, Theerachai
The fabrication of 0.62[0.75Pb(Mg<inf>1/3</inf>Nb<inf>2/3</inf>)O <inf>3</inf>-0.25Pb(Yb<inf>1/2</inf>Nb<inf>1/2</inf>)O<inf>3</inf>]-0. 38PbTiO<inf>3</inf> ceramics (abbreviated PMN-PYbN-PT) by combustion technique using one step calcination was studied. Glycine was used as fuel to reduce the reaction temperature. The phase formation, microstructure, density and dielectric properties were investigated. It was shown that calcination method is more effective than conventional solid state reaction. The crystal structure of PMN-PYbN-PT ceramics exhibited a single rhombohedral perovskite phase in samples sintered at temperature T < 1200°C. The pyrochlore phase was found in the samples sintered at 1200°C. The average grain size of the ceramics increases with increasing sintering temperature. The density and the maximum dielectric constant increases with increasing sintering temperatures up to 1150°C, and then decreases at higher temperatures. The maximum density (8.04 g/cm3), highest dielectric constant (19000) and excellent ferroelectric properties (P<inf>r</inf> ∼ 41.05 μC/cm2and E<inf>c</inf> ∼ 8.1 kV/cm) were obtained for the sample sintered at 1150°C. © 2013 Copyright Taylor and Francis Group, LLC.

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