Specific absorption rate of assembly of magnetic nanoparticles with uniaxial anisotropy

Usov, N. A.; Gubanova, Elizaveta M; Wei, Zung‐Hang

doi:10.1088/1742-6596/1439/1/012044

Cited by 10 publications

(15 citation statements)

References 45 publications

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“…Note that earlier [30] a similar behavior of SAR was revealed for randomly oriented assemblies of spherical iron oxide nanoparticles with saturation magnetization Ms = 350 emu/cm 3 depending on the value of the effective uniaxial magnetic anisotropy constant in the range Ku = 10 4 -510 5 erg/cm 3 .…”

Section: Sar Of Dilute Randomly Oriented Assemblysupporting

confidence: 73%

“…In theoretical studies [18][19][20][21][22][23] spherical magnetic nanoparticles are usually considered. A theoretical study of assemblies of spherical nanoparticles with 10 uniaxial [18][19][20][21]23,30] and cubic [25] magnetic anisotropy showed the existence of an interval of optimal nanoparticle diameters where the SAR of the assembly reaches maximum at a given frequency and amplitude of ac magnetic field. In this work, using numerical simulation, similar results were obtained for spheroidal magnetite nanoparticles in the range of aspect ratios a/b = 1.0 -3.0.…”

Section: Discussionmentioning

confidence: 99%

“…For example, the use of magnetic nanoparticles with increased value of magnetic anisotropy constant was assumed [28,29] to be promising in magnetic hyperthermia. However, numerical simulation [30] showed that for spherical nanoparticles increase of the uniaxial anisotropy constant leads to a decrease in SAR and a shift of the optimal particle diameters to smaller dimensions.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Heating ability of elongated magnetic nanoparticles

Gubanova¹,

Usov²,

Oleinikov³

2021

Preprint

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Low-frequency hysteresis loops and specific absorption rate (SAR) of various assemblies of elongated spheroidal magnetite nanoparticles have been calculated for a range of particle semiaxis ratios a/b = 1.0 – 3.0. The SAR of a dilute randomly oriented assembly of magnetite nanoparticles in an alternating magnetic field of moderate frequency, f = 300 kHz, and amplitude H0 = 100 - 200 Oe is shown to decrease significantly with an increase in the aspect ratio of nanoparticles. In addition, there is a narrowing and shift of the intervals of optimal particle diameters towards smaller particle sizes. However, the orientation of a dilute assembly of elongated nanoparticles in a magnetic field leads to an almost twofold increase in SAR at the same frequency and amplitude of the alternating magnetic field, the range of optimal particle diameters remaining unchanged. The effect of the magneto-dipole interaction on the SAR of an assembly of oriented clusters of elongated magnetite nanoparticles has also been investigated depending on the volume fraction of nanoparticles in a cluster. It has been found that the SAR of the assembly of oriented clusters decreases by approximately an order of magnitude with an increase in the volume fraction of nanoparticles in a cluster in the range 0.04 - 0.2.

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Section: Sar Of Dilute Randomly Oriented Assemblysupporting

confidence: 73%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Heating ability of elongated magnetic nanoparticles

Gubanova¹,

Usov²,

Oleinikov³

2021

Preprint

View full text Add to dashboard Cite

show abstract

“…Here,

, where

is the frequency dependent hysteresis loop area for an alternating magnetic field in terms of the nanoparticle magnetization M , and the external magnetic field

. The value of A strongly depends on the size of the magnetic nanoparticles and there is always an optimal size of magnetic nanoparticles for which the heating rate is the highest [ 71 , 72 ]. This applies also to iron-based colloids in alkaline conditions [ 50 ].…”

Section: Discussionmentioning

confidence: 99%

Filtration of Nanoparticle Agglomerates in Aqueous Colloidal Suspensions Exposed to an External Radio-Frequency Magnetic Field

et al. 2021

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The study investigated the phenomenon of the fast aggregation of single-domain magnetic iron oxide nanoparticles in stable aqueous colloidal suspensions due to the presence of a radio-frequency (RF) magnetic field. Single-domain nanoparticles have specific magnetic properties, especially the unique property of absorbing the energy of such a field and releasing it in the form of heat. The localized heating causes the colloid to become unstable, leading to faster agglomeration of nanoparticles and, consequently, to rapid sedimentation. It has been shown that the destabilization of a stable magnetic nanoparticle colloid by the RF magnetic field can be used for the controlled filtration of larger agglomerates of the colloid solution. Two particular cases of stable colloidal suspensions were considered: a suspension of the bare nanoparticles in an alkaline solution and the silica-stabilized nanoparticles in a neutral solution. The obtained results are important primarily for biomedical applications and wastewater treatment.

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“…For example, the use of magnetic nanoparticles with increased value of magnetic anisotropy constant was assumed [ 28 – 29 ] to be promising in magnetic hyperthermia. However, numerical simulations [ 30 ] showed that for spherical nanoparticles an increase of the uniaxial anisotropy constant leads to a decrease in SAR and a shift of the optimal particle diameters to smaller dimensions.…”

Section: Introductionmentioning

confidence: 99%

Heating ability of elongated magnetic nanoparticles

Gubanova¹,

Usov²,

Oleinikov³

2021

Beilstein J. Nanotechnol.

View full text Add to dashboard Cite

Low-frequency hysteresis loops and specific absorption rate (SAR) of various assemblies of elongated spheroidal magnetite nanoparticles have been calculated for a range of particle semiaxis ratios a/b = 1.0–3.0. The SAR of a dilute randomly oriented assembly of magnetite nanoparticles in an alternating magnetic field of moderate frequency, f = 300 kHz, and amplitude H0 = 100–200 Oe is shown to decrease significantly with an increase in the aspect ratio of nanoparticles. In addition, there is a narrowing and shift of the intervals of optimal particle diameters towards smaller particle sizes. However, the orientation of a dilute assembly of elongated nanoparticles in a magnetic field leads to an almost twofold increase in SAR at the same frequency and amplitude of the alternating magnetic field, the range of optimal particle diameters remaining unchanged. The effect of the magneto-dipole interaction on the SAR of a dilute assembly of oriented clusters of elongated magnetite nanoparticles has also been investigated depending on the volume fraction of nanoparticles in a cluster. It has been found that the SAR of the assembly of oriented clusters decreases by approximately an order of magnitude with an increase in the volume fraction of nanoparticles in a cluster in the range of 0.04–0.2.

show abstract

Specific absorption rate of assembly of magnetic nanoparticles with uniaxial anisotropy

Cited by 10 publications

References 45 publications

Heating ability of elongated magnetic nanoparticles

Heating ability of elongated magnetic nanoparticles

Filtration of Nanoparticle Agglomerates in Aqueous Colloidal Suspensions Exposed to an External Radio-Frequency Magnetic Field

Heating ability of elongated magnetic nanoparticles

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