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Optimal Bi₀.₈Ba₀.₂FeO₃ doping in Bi₀.₅(Na₀.₇₇K₀.₂₀Li₀.₀₃)₀.₅TiO₃ multiferroic ceramics synthesized by the solid-state combustion technique
(2025-12-01)
Thawong, Pichittra
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Prasertpalichat, Sasipohn
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Suriwong, Tawat
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Pinitsoontorn, Supree
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Jantaratana, Pongsakorn
(1-x)Bi<inf>0.5</inf>(Na<inf>0.77</inf>K<inf>0.20</inf>Li<inf>0.03</inf>)<inf>0.5</inf>TiO<inf>3</inf>-xBi<inf>0.8</inf>Ba<inf>0.2</inf>FeO<inf>3</inf> ((1-x)BNKLT-xBBF) ceramics with x = 0-0.4 were synthesized by the solid-state combustion technique. X-ray diffraction (XRD) analysis confirmed a pure perovskite structure with coexisting rhombohedral and tetragonal phases. Rietveld refinement revealed that the unit cell volume increased with increased x due to the substitution of smaller Bi3+ and Ti4+ ions by larger Ba2+ and Fe3+ ions at the A- and B-sites, respectively. The average grain size and measured density also increased with increasing x, while the resistivity decreased. At room temperature, (1-x)BNKLT-xBBF ceramics with x = 0.2–0.4 exhibited multiferroic behavior, characterized by ferroelectric and ferromagnetic hysteresis loops. The 0.8BNKLT-0.2BBF ceramic exhibited the most favorable properties, including: the highest relative density (95.48%), the highest dielectric constant and low dielectric loss at room temperature (ε<inf>R</inf> = 1746 and tan δ<inf>R</inf> = 0.0296), good ferroelectric properties (P<inf>r</inf>=6.46 µC/cm2 and E<inf>c</inf>=11.84 kV/cm) and good ferromagnetic properties (M<inf>r</inf>=0.002 emu/g, H<inf>c</inf>=110 Oe and α<inf>E</inf> = 1.092 mV/Oe·cm). These results indicate that 0.8BNKLT-0.2BBF has the potential for applications in lead-free, room temperature multiferroic applications.
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Novel magnetically interconnected micro/macroporous structure of monolithic porous carbon adsorbent derived from sodium alginate and wasted black liquor and its adsorption performance
(2021-01-01)
Onsri, Parichart
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Dechtrirat, Decha
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Nooeaid, Patcharakamon
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Eiad-Ua, Apiluck
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Amornpitoksuk, Pongsaton
The novel and facile preparation of magnetically interconnected micro/macroporous structure of monolithic porous carbon adsorbent (MPCA) were designed and presented herein. The synthesis was achieved via conventional freeze-drying and pyrolysis processes. In this study, sodium alginate and wasted black liquor were employed as starting pre-cursors. Sodium alginate acts as a template of materials, whereas black liquor, the wasted product from the paper industry with plentiful of lignin content and alkaline solution, played an essential role in the reinforcement and activation of porosity for the resulting materials. Moreover, both the precursors were well dissolved in Fe3+ solution, providing a simple addition of a magnetic source in a one-pot synthesis. The interconnected micro/macroporous structures were generated through freeze-drying and, subsequently the pyrolysis process. The obtained cylindrical-shaped monolithic porous carbon adsorbent (MPCA-700) showed high mechanical stability, a high BET specific surface area (902 m2/g). Such aforementioned features were considered suitable to make the synthesized monolith as an adsorbent for the removal of heavy metal ions. The maximum adsorption capacity of MPCA-700 towards Pb2+ ions was 76.34 mg/g at pH 5. The adsorption studies illustrated that adsorption kinetics and isotherm perfectly fitted with the pseudo-second-order kinetics model and Langmuir isotherm, respectively. This work presents a promising pro-tocol to reduce the overall costs in the preparation of renewable adsorbents with good adsorption efficiency and regeneration.
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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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X-ray absorption spectroscopy analysis and magnetic properties of M-doped TiO2 nanoparticles (M=Co, Mn, Ni and Zn) prepared by co-precipitation method
(2017-08-01)
Wattanawikkam, Chakkaphan
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Pecharapa, Wisanu
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Ishihara, Keiichi N.
M-doped TiO<inf>2</inf> nanoparticles (M=Co, Mn, Ni and Zn) were synthesized by co-precipitation method combined with annealing at 500 °C for 2 h. X-ray diffraction (XRD) was used to identify their structural phases. X-ray absorption near edge structure (XANES) was conducted to probe the chemical state and crystal atomic structure of prepared samples. Magnetic properties of all samples were characterized by vibrating sample magnetrometer (VSM). The XRD analyses reveal that all samples crystallize in anatase tetragonal structure with no additional peaks. The XANES spectra exhibit triple pre-edge fingerprint of Ti4+ of oxidation state with six-fold octahedral coordinate structure. Co-, Ni- and Zn- K-edge results indicate that the Co, Ni and Zn ions in M-doped TiO<inf>2</inf> are in 2+ formal oxidation state. Meanwhile, Mn-doped TiO<inf>2</inf> sample contains the different oxidation states of 3+ and 4+. The amount of each oxidation state is confirmed by using linear combination fitting method. The magnetic measurement illustrates the paramagnetic behavior for Co-, Mn- and Ni- doped samples that strongly depend on the doping content and no hysteresis loop is observed in undoped and Zn-doped samples.
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Structural, optical and magnetic properties of diluted magnetic perovskite ZnTiO3 doped with Co and Mn prepared by sonochemical method
(2017-01-01)
Wattanawikkam, Chakkaphan
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Phoohinkong, Weerachon
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Pecharapa, Wisanu
We employed a sonochemical method to fabricate transition metal ion doped perovskite ZnTiO<inf>3</inf> (M-ZnTiO<inf>3</inf>) nanoparticles, including individual Co and Mn ions. The Zn:Ti was mixed in molar ratio of 1:1 to obtain starting precursor for ZnTiO<inf>3</inf>. The different concentrations of Co (5-10 mol%) and Mn (3-7 mol%) were doped in ZnTiO<inf>3</inf>, then the mixing solution were irradiated in high frequency ultrasound of a sonometer (20 kHz, 750 W) at room temperature to obtain the as-prepared samples. The final products were calcined at 800°C for 3 h to improve the crystallinity. We confirmed formation structures of M-ZnTiO<inf>3</inf> nanoparticles by X-ray diffraction (XRD), and used X-ray absorption near edge spectroscopy (XANES) and X-ray photoelectron spectroscopy (XPS) technique to investigate the crystal structure and valence states of the sample. Meanwhile, we studied their optical properties by diffuse reflectance spectroscopy, and evaluated magnetic properties of the samples at room temperature by vibrating sample magnetometer (VSM). Magnetization measurements revealed the paramagnetic behavior for Co-ZnTiO<inf>3</inf> and weak ferromagnetic behavior for Mn-ZnTiO<inf>3</inf>. We also investigated and discussed the effect of metal ion doping concentration on the structural, optical and magnetic properties.
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Investigation on ferromagnetic and ferroelectric properties of (La, K)-doped BiFeO3-BaTiO3 solid solution
(2013-05-01)
Prasatkhetragarn, Anurak
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Muangkonkad, Pantip
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Aommongkol, Parichart
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Jantaratana, Pongsakorn
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Vittayakorn, Naratip
Multiferroic materials of BiFeO<inf>3</inf>-BaTiO<inf>3</inf> solid solution have been fabricated in order to improve ferromagnetic and ferroelectric properties. The effects of La (1 mol%) and K (varied from 0.5-5 mol%) doped 0.75BiFeO<inf>3</inf>-0.25BaTiO<inf>3</inf> on phase formation, ferromagnetic and ferroelectric properties have been investigated and discussed. The rhombohedral perovskite phase of specimens was characterized by XRD technique. Fracture morphology reveals the grain growth characteristics with increasing K content. (La, K)-doped 0.75BiFeO<inf>3</inf>-0.25BaTiO<inf>3</inf> with La=1 mol% and K=3 mol% exhibits the highest remnant polarization and remnant magnetization. © 2012 Elsevier Ltd and Techna Group S.r.l.
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A simple route to synthesize nickel ferrite (NiFe2O4) nanoparticles using egg white
(2007-05-01)
Maensiri, Santi
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Masingboon, Chivalrat
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Boonchom, Banjong
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Seraphin, Supapan
NiFe<inf>2</inf>O<inf>4</inf> nanoparticles were synthesized by a simple and cost-effective method using Ni and Fe nitrates and freshly extracted egg white (ovalbumin) in an aqueous medium. The X-ray diffraction and selected-area electron diffraction results indicated that the synthesized nanoparticles have only the inverse spinel structure without the presence of any other phase impurities. Room temperature magnetization results showed a ferromagnetic behavior of the NiFe<inf>2</inf>O<inf>4</inf> nanoparticles, with saturation-specific magnetization values in the range of 26.4-42.5 emu/g at 10 kOe. © 2006 Acta Materialia Inc.

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