Structural Rietveld Refinement and Vibrational Study of M-Type BaFe12O19 Nanoparticles

Ананд, С.; Pauline, S.; Vinosel, V. Maria; Janifer, M. Asisi

doi:10.1016/j.matpr.2019.02.141

Cited by 32 publications

(15 citation statements)

References 8 publications

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“…The phase equilibria in the quasi‐binary systems BaO–Fe 2 O 3 and Nd 2 O 3 –BaO at 1373 K in air and the crystal structure of the complex oxides formed in these systems were presented in our early papers 40,51 . The existence of only NdFeO 3 was confirmed in the Nd 2 O 3 –Fe 2 O 3 system at 1373 K in air, which is in a good agreement with the results reported earlier 29–32 . The chemical formulas and unit cell parameters of stable ternary oxides are listed in Table 1.…”

Section: Resultssupporting

confidence: 84%

“…Several ternary oxides were described in the BaO–Fe 2 O 3 system: BaFe 12 O 19 , BaFe 2 O 4 , Ba 2 Fe 2 O 5 (or BaFeO 3‐ δ ), Ba 3 Fe 2 O 6 , and Ba 5 Fe 2 O 8 , 28,29 however, only the first three are stable at 1373 K in air. Fe‐richest oxide, the BaFe 12 O 19 hexaferrite, crystallizes in the hexagonal structure (SG P 6 3 / mmc ), with the unit cell parameters: a = 5.89 Å and c = 23.23 Å 30 . BaFe 2 O 4 was prepared by the citrate‐nitrate combustion process 31,32 or by the Pechini method 33 .…”

Section: Introductionmentioning

confidence: 99%

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Phase equilibria in the Nd₂O₃–BaO–Fe₂O₃ system: Crystal structure, oxygen content, and properties of intermediate oxides

et al. 2022

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The phase equilibria in the ½Nd 2 O 3 -BaO-½Fe 2 O 3 system were systematically studied at 1373 K in air and presented in the form of a phase diagram. By X-ray diffraction (XRD) analysis of quenched samples, the homogeneity ranges and crystal structure were determined for the following intermediate oxides: Nd 1-x Ba x FeO 3-δ with 0.0 ≤ x ≤ 0.05 (space group (SG) Pnma) and with 0.6 ≤ x ≤ 0.7 (SG Pm-3m), Ba 6+y Nd 2-y Fe 4 O 15-δ with 0.0 ≤ y ≤ 0.4 (SG P6 3 mc), and Ba 1.1 Nd 1.9 Fe 2 O 7-δ (SG P4 2 /mnm). The structural parameters of single-phase oxides were refined by the Rietveld method. The changes in oxygen content for Nd 1-x Ba x FeO 3-δ (0.6 ≤ x ≤ 0.7), Ba 6 Nd 2 Fe 4 O 15-δ , and Ba 1.1 Nd 1.9 Fe 2 O 7-δ versus temperature in air were determined by thermogravimetric analysis. Gradual substitution of neodymium by barium in the Nd 1-x Ba x FeO 3-δ (0.6 ≤ x ≤ 0.7) oxides leads to a decrease of oxygen content. Partial ordering via formation of separate domains with a p × a p × 5a p superstructure in Nd 0.4 Ba 0.6 FeO 3-δ , which cannot be detected by XRD, noticeably influence its thermal expansion and electrical conductivity.

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Section: Resultssupporting

confidence: 84%

Section: Introductionmentioning

confidence: 99%

Phase equilibria in the Nd₂O₃–BaO–Fe₂O₃ system: Crystal structure, oxygen content, and properties of intermediate oxides

et al. 2022

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“…The Raman spectral data of the specimens were found to be in good agreement with the data reported in literature. 31,32 The major peaks observed at about 684.2, 528, 409.5 and 330 cm À1 were consistent with the magnetoplumbite structure. The peaks at 684 cm À1 can be assigned to Fe-O bonds at the tetrahedral 4f1 and bipyramidal 2b sites.…”

Section: Effects Of Alkali Environment On Phase Compositionsupporting

confidence: 67%

Hydrothermal synthesis and competitive growth of flake-like M-type strontium hexaferrite

et al. 2019

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In this paper, single flake-like strontium hexaferrite was directly synthesized via a modified hydrothermal approach without high-temperature annealing. To determine the main factors governing the formation of the hexaferrite phase and impurity a-Fe 2 O 3 , effects of alkali environment and concentrations of metal ions on phase composition, grain growth, and magnetic properties were systematically analyzed. Results from XRD, FESEM and FT-IR analyses indicated that initial alkali concentration was the key factor influencing the phase composition of particles. Suitable initial alkali environment can enhance the nucleation and growth of ferrite, and inhibit the formation of by-product a-Fe 2 O 3 at the same time. It was also found that the increase in initial concentration of strontium ions could improve the nucleation of hexaferrite and reduce the grain size, and consequently, change the magnetic performance of hexagonal particles. When the molar ratios of ferric ions to strontium ions were constant, the average grain size did not change significantly with the initial concentration of iron ions, which could be attributed to high levels of strontium ions and hydroxyl ions in the reaction system. The abovementioned results indicate that the optimized hydrothermal conditions are beneficial for the formation of a single phase and for controlling the particle size and magnetic properties of M-type hexaferrite.

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“…From the results obtained, AA 2024 + 4% CNT + 2% Si composites shows low dielectric constant and low dielectric loss. Dielectric materials with low-loss are widely employed in communication systems and also in quite a lot of electronic devices [34][35][36][37].…”

Section: Calculation Of Particle Sizementioning

confidence: 99%

Structural Characterization and Dielectric Properties of the Effect of Carbon Nanotubes and Silicon on AA2024 Metal Matrix Composites

Mani

2021

Preprint

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This research work focus on the formation of AA2024-carbon nanotubes-silicon hybrid metal matrixcomposites. Structure morphology, structural characterization, elemental identification and dielectric properties of AA 2024 in the presence of carbon nanotubes, silicon andits combinations at various proportions was evaluated using SEM, XRD, EDX and Hioki 3532-50 LCR Hi-Tester. A two-stage stir casting method was used for the fabrication of AA2024 hybrid metal matrix composites. It was observed that the size of the AA 2024 + 4% CNT + 2% Si composite wasfound to be 23.6 nm, this shows enhanced results than other composites prepared. Dielectric properties of composites were characterized as a function of composition and frequency. It was found that the dielectric constant, dielectric loss and dissipation factor decreases smoothly with an increase of reinforcements and also frequency.

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Structural Rietveld Refinement and Vibrational Study of M-Type BaFe12O19 Nanoparticles

Cited by 32 publications

References 8 publications

Phase equilibria in the Nd₂O₃–BaO–Fe₂O₃ system: Crystal structure, oxygen content, and properties of intermediate oxides

Phase equilibria in the Nd₂O₃–BaO–Fe₂O₃ system: Crystal structure, oxygen content, and properties of intermediate oxides

Hydrothermal synthesis and competitive growth of flake-like M-type strontium hexaferrite

Structural Characterization and Dielectric Properties of the Effect of Carbon Nanotubes and Silicon on AA2024 Metal Matrix Composites

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Structural Rietveld Refinement and Vibrational Study of M-Type BaFe12O19 Nanoparticles

Cited by 32 publications

References 8 publications

Phase equilibria in the Nd2O3–BaO–Fe2O3 system: Crystal structure, oxygen content, and properties of intermediate oxides

Phase equilibria in the Nd2O3–BaO–Fe2O3 system: Crystal structure, oxygen content, and properties of intermediate oxides

Hydrothermal synthesis and competitive growth of flake-like M-type strontium hexaferrite

Structural Characterization and Dielectric Properties of the Effect of Carbon Nanotubes and Silicon on AA2024 Metal Matrix Composites

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Phase equilibria in the Nd₂O₃–BaO–Fe₂O₃ system: Crystal structure, oxygen content, and properties of intermediate oxides

Phase equilibria in the Nd₂O₃–BaO–Fe₂O₃ system: Crystal structure, oxygen content, and properties of intermediate oxides