Structure and magnetic properties of silica-coated magnetite-nanoparticle composites

Husain, Halimah; Hariyanto, B; Sulthonul, M.; Klysubun, Wantana; Darminto, D.; Pratapa, Suminar

doi:10.1088/2053-1591/ab29af

Cited by 18 publications

(9 citation statements)

References 43 publications

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“…Ni is a well-known ferromagnetic element, while Ni 3 C is known to be non-ferromagnetic. The gradual decrease in Ms can be explained by the magnetization reversal due to two causes: (1) The amount of Ni inside the particles is consumed due to the formation of the shell, and (2) the magnetic field transmission is disturbed due to the presence of the non-ferromagnetic shell [39,40].…”

Section: Resultsmentioning

confidence: 99%

Simple Synthesis and Characterization of Shell-Thickness-Controlled Ni/Ni3C Core-Shell Nanoparticles

Woo

Suh

2022

Nanomaterials

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Ni/Ni3C core-shell nanoparticles with an average diameter of approximately 120 nm were carburized via a chemical solution method using triethylene glycol. It was found that over time, the nanoparticles were covered with a thin Ni3C shell measuring approximately 1–4 nm, and each Ni core was composed of poly grains. The saturation magnetization of the core-shell nanopowders decreased in proportion to the amount of Ni3C. The synthesis mechanism of the Ni/Ni3C core-shell nanoparticles was proposed through X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) analyses.

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Section: Resultsmentioning

confidence: 99%

Simple Synthesis and Characterization of Shell-Thickness-Controlled Ni/Ni3C Core-Shell Nanoparticles

Woo

Suh

2022

Nanomaterials

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“…In the literature, the specifics of the XRD peaks with determined crystallite sizes by Scherrer's formula have been thoroughly explored. 40 Figure 2a,b exhibits the crystal structure of Fe 3 O 4 and SiO 2 . One can anticipate that such an Fe 3 O 4 matrix is engulfed in the SiO 2 matrix.…”

Section: T H Imentioning

confidence: 99%

Origin of Enhancement of Orbital Magnetic Moment in SiO₂-Coated Fe₃O₄ Nanocomposites Studied by X-ray Magnetic Circular Dichroism

Dawn,

Tjiu,

Aabdin

et al. 2023

Langmuir

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In this study, magnetic Fe3O4 nanoparticles (NPs) were dispersed uniformly by varying the thickness of the SiO2 coating, and their electronic and magnetic properties were investigated. X-ray diffraction confirmed the structural configuration of monophase inverse-spinel Fe3O4 NPs in nanometer size. Scanning electron microscopy revealed the formation of proper nonporous crystallite particles with a clear core–shell structure with silica on the surface of Fe3O4 NPs. The absorption mechanism studied through the zeta potential indicates that SiO2-coated Fe3O4 nanocomposites (SiO2@Fe3O4 NCs) possess electrostatic interactions to control their agglomeration in stabilizing suspensions by providing a protective shield of amorphous SiO2 on the oxide surface. High-resolution transmission electron microscopy images demonstrate a spherical morphology having an average grain diameter of ∼11–17 nm with increasing thickness of SiO2 coating with the addition of a quantitative presence and proportion of elements determined through elemental mapping and electron energy loss spectroscopy studies. Synchrotron-based element-specific soft X-ray absorption spectroscopy and X-ray magnetic circular dichroism (XMCD) techniques have been involved in the bulk-sensitive total fluorescence yield mode to understand the origin of magnetization in SiO2@Fe3O4 NCs. The magnetization hysteresis of Fe3O4 was determined by XMCD. At room temperature, the magnetic coercivity (H c) is as high as 1 T, which is about 2 times more than the value of the thin film and about 5 times more pronounced than that of NPs. For noninteracting single-domain NPs with the H c spread from 1 to 3 T, the Stoner–Wohlfarth model provided an intriguing explanation for the hysteresis curve. These curves determine the different components of Fe oxides present in the samples that derive the remnant magnetization involved in each oxidation state of Fe and clarify which Fe component is responsible for the resultant magnetism and magnetocrystalline anisotropy based on noninteracting single-domain particles.

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“…However, the absolute magnetization value of the nanocomposite decreases with the increase of the SiO 2 shell thickness. [101] A modified Stober method was employed for the synthesis of Fe 3 O 4 @SiO 2 nanocomposites using 20 nm hydrophilic Fe 3 O 4 NPs as seeds. The "common" Stober method is the alkaline hydrolysis of TEOS.…”

Section: Silica-coated Magnetic Nanocompositesmentioning

confidence: 99%

“…However, the absolute magnetization value of the nanocomposite decreases with the increase of the SiO 2 shell thickness. [ 101 ]…”

Section: Magnetic Nanoparticles With Inorganic Compositesmentioning

confidence: 99%

Magnetic Nanoparticle Composites: Synergistic Effects and Applications

2021

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Composite materials are made from two or more constituent materials with distinct physical or chemical properties that, when combined, produce a material with characteristics which are at least to some degree different from its individual components. Nanocomposite materials are composed of different materials of which at least one has nanoscale dimensions. Common types of nanocomposites consist of a combination of two different elements, with a nanoparticle that is linked to, or surrounded by, another organic or inorganic material, for example in a core‐shell or heterostructure configuration. A general family of nanoparticle composites concerns the coating of a nanoscale material by a polymer, SiO2 or carbon. Other materials, such as graphene or graphene oxide (GO), are used as supports forming composites when nanoscale materials are deposited onto them. In this Review we focus on magnetic nanocomposites, describing their synthetic methods, physical properties and applications. Several types of nanocomposites are presented, according to their composition, morphology or surface functionalization. Their applications are largely due to the synergistic effects that appear thanks to the co‐existence of two different materials and to their interface, resulting in properties often better than those of their single‐phase components. Applications discussed concern magnetically separable catalysts, water treatment, diagnostics‐sensing and biomedicine.

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Structure and magnetic properties of silica-coated magnetite-nanoparticle composites

Cited by 18 publications

References 43 publications

Simple Synthesis and Characterization of Shell-Thickness-Controlled Ni/Ni3C Core-Shell Nanoparticles

Simple Synthesis and Characterization of Shell-Thickness-Controlled Ni/Ni3C Core-Shell Nanoparticles

Origin of Enhancement of Orbital Magnetic Moment in SiO₂-Coated Fe₃O₄ Nanocomposites Studied by X-ray Magnetic Circular Dichroism

Magnetic Nanoparticle Composites: Synergistic Effects and Applications

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Structure and magnetic properties of silica-coated magnetite-nanoparticle composites

Cited by 18 publications

References 43 publications

Simple Synthesis and Characterization of Shell-Thickness-Controlled Ni/Ni3C Core-Shell Nanoparticles

Simple Synthesis and Characterization of Shell-Thickness-Controlled Ni/Ni3C Core-Shell Nanoparticles

Origin of Enhancement of Orbital Magnetic Moment in SiO2-Coated Fe3O4 Nanocomposites Studied by X-ray Magnetic Circular Dichroism

Magnetic Nanoparticle Composites: Synergistic Effects and Applications

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Origin of Enhancement of Orbital Magnetic Moment in SiO₂-Coated Fe₃O₄ Nanocomposites Studied by X-ray Magnetic Circular Dichroism