Simultaneous enhancements of remanence and (BH)max in BaFe12O19/CoFe2O4 nanocomposite powders

Yang, Haibo; Liu, Miao; Lin, Ying; Yang, Yanyan

doi:10.1016/j.jallcom.2015.01.012

Cited by 54 publications

(15 citation statements)

References 21 publications

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“…Kneller et al [9] have proposed that permanent magnets could be produced based on composite materials comprising two appropriately dispersed hard and soft magnetic phases that are mutually exchange-coupled. The large coercivity (provided by hard magnetic phase) and the high saturation magnetization (provided by soft magnetic phase) of magnetic hard/soft ferrites composites can be achieved when the exchange coupling is performed [10][11][12][13]. Many researchers have reported the exchange coupling behavior for some multilayer and metal alloy systems like Nd-Fe-B [14], SmCo x -Co [15], Pr 2 Fe 12 B [16], and Sm-Co/Fe [17].…”

Section: Introductionmentioning

confidence: 99%

Functional Sr0.5Ba0.5Sm0.02Fe11.98O4/x(Ni0.8Zn0.2Fe2O4) Hard–Soft Ferrite Nanocomposites: Structure, Magnetic and Microwave Properties

et al. 2020

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This paper reports the correlation between the composition of the functional Sr0.5Ba0.5Sm0.02Fe11.98O19/x(Ni0.8Zn0.2Fe2O4) hard–soft nanocomposites (SrBaSmFe/x(NiZnFe) NCs), where 0.0 ≤ x ≤ 3.0, and their structural features, magnetic, and microwave properties. SrBaSmFe/x(NiZnFe) hard/soft ferrite NCs are produced using the one-pot citrate combustion method. According to the XRD analysis, all samples showed the co-existence of both SrBaSmFe and NiZnFe phases in different ratios. Magnetic properties are measured in a wide range of magnetic fields and temperatures (10 and 300 K) and correlated well with the composition of the investigated samples. The microwave properties (frequency dispersions of the magnetic permeability, and electrical permittivity) are discussed by using the co-axial method in the frequency range of 0.7–18 GHz. Non-linear dependences of the main microwave features were observed with varying of composition. The microwave behavior correlated well with the composite theory. These results could be used in practice for developing antenna materials.

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Section: Introductionmentioning

confidence: 99%

Functional Sr0.5Ba0.5Sm0.02Fe11.98O4/x(Ni0.8Zn0.2Fe2O4) Hard–Soft Ferrite Nanocomposites: Structure, Magnetic and Microwave Properties

et al. 2020

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“…It was revealed that both a int and D grain were independent of BH max in the given D grain range of 8-64 nm. Theoretically, for granular magnets of well-aligned easy axes, BH max depends only on the remanence squared, provided that the coercivity is greater than M r /2 , where M r is the remanence 12,30 . Indeed, in our datasets, the remanence showed a strong correlation with the misalignment of easy axes, as shown in Supplementary Information Sect.…”

Section: Resultsmentioning

confidence: 99%

Optimizing machine learning models for granular NdFeB magnets by very fast simulated annealing

Park

Lee

et al. 2021

Sci Rep

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The macroscopic properties of permanent magnets and the resultant performance required for real implementations are determined by the magnets’ microscopic features. However, earlier micromagnetic simulations and experimental studies required relatively a lot of work to gain any complete and comprehensive understanding of the relationships between magnets’ macroscopic properties and their microstructures. Here, by means of supervised learning, we predict reliable values of coercivity (μ0Hc) and maximum magnetic energy product (BHmax) of granular NdFeB magnets according to their microstructural attributes (e.g. inter-grain decoupling, average grain size, and misalignment of easy axes) based on numerical datasets obtained from micromagnetic simulations. We conducted several tests of a variety of supervised machine learning (ML) models including kernel ridge regression (KRR), support vector regression (SVR), and artificial neural network (ANN) regression. The hyper-parameters of these models were optimized by a very fast simulated annealing (VFSA) algorithm with an adaptive cooling schedule. In our datasets of randomly generated 1,000 polycrystalline NdFeB cuboids with different microstructural attributes, all of the models yielded similar results in predicting both μ0Hc and BHmax. Furthermore, some outliers, which deteriorated the normality of residuals in the prediction of BHmax, were detected and further analyzed. Based on all of our results, we can conclude that our ML approach combined with micromagnetic simulations provides a robust framework for optimal design of microstructures for high-performance NdFeB magnets.

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“…BaFe 12 O 19 /CoFe 2 O 4 @polyethylene glycol nanocomposites (BFO/CFO@PEG nanocomposites) synthesized using via sol-gel method [ 46 ].…”

Section: Methodsmentioning

confidence: 99%

“…Hexagonal barium ferrites composites have been previously applied owing to the expectation of high remaining magnetization and high energy product by using micromagnetic calculations, high-density magnetic recording, microwave devices, and magnetofluid medicine [ 46 ]. Roy et al (2009) examined the use of BaFe 12 O 19 /Ni 0.8 Zn 0.2 Fe 2 O 4 composite powders finding out the effect of temperature coercivity [ 47 ].…”

Section: Introductionmentioning

confidence: 99%

Barium/Cobalt@Polyethylene Glycol Nanocomposites for Dye Removal from Aqueous Solutions

Rahdar

Sattari

et al. 2021

Polymers

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Dyes are known as one of the most dangerous industrial pollutants which can cause skin diseases, allergy, and provoke cancer and mutation in humans. Therefore, one of the important environmental issues is the effective removal of dyes from industrial wastewater. In the current work, BaFe12O19/CoFe2O4@polyethylene glycol (abbreviated as BFO/CFO@PEG) nanocomposite was synthesized and evaluated regarding its capacity for adsorptive removal of a model dye Acid Blue 92 (denoted as AB92) from aqueous solutions. The characteristics of the prepared nanocomposite was determined by tests such as X-ray diffraction (XRD), scanning electron microscope (SEM), vibration sample magnetization (VSM), and Fourier transform infrared spectroscopy (FTIR). The effects of conditional parameters including pH (2–12), initial concentration of dye (20–100 mg/L), adsorbent dosage (0.02–0.1 g/L) and contact time (0-180 min) on the adsorption of dye were investigated and then optimized. The results indicated that with the increase of the adsorbent dosage from 0.02 to 0.1 g/L, the removal efficiency increased from 74.1% to 78.6%, and the adsorbed amount decreased from 148.25 to 31.44 mg/g. The maximum removal efficiency (77.54%) and adsorption capacity (31.02 mg/g) were observed at pH 2. Therefore, the general optimization conditions revealed that the maximum adsorption efficiency of dye was obtained in condition of initial concentration of 20 mg/L, contact time of 1 h and pH of solution equal 2. The adsorption isotherm and kinetic data were evaluated using a series of models. The pseudo-second order kinetic model and Freundlich isotherm model show the best fitting with experimental data with R2∼0.999.

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Simultaneous enhancements of remanence and (BH)max in BaFe12O19/CoFe2O4 nanocomposite powders

Cited by 54 publications

References 21 publications

Functional Sr0.5Ba0.5Sm0.02Fe11.98O4/x(Ni0.8Zn0.2Fe2O4) Hard–Soft Ferrite Nanocomposites: Structure, Magnetic and Microwave Properties

Functional Sr0.5Ba0.5Sm0.02Fe11.98O4/x(Ni0.8Zn0.2Fe2O4) Hard–Soft Ferrite Nanocomposites: Structure, Magnetic and Microwave Properties

Optimizing machine learning models for granular NdFeB magnets by very fast simulated annealing

Barium/Cobalt@Polyethylene Glycol Nanocomposites for Dye Removal from Aqueous Solutions

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