Study of specific loss power of magnetic fluids with various viscosities

In this study, the influence of particle size distribution in the range of σ =0-0.4 on the specific loss power (SLP) in magnetic fluids based on nanoparticles (NPs) of 6 materials of FeCo, La0.3Sr0.7MnO3, MnFe2O4, g-Fe2O3, CoFe2O4 and FePt was evaluated using Linear Response Theory (LRT). Results show that while the particle diameters Dcp of maximum SLP remain unchanged, the SLPmax values decrease with increasing size distribution for all the studied materials. The reduction behaviors can be classified into 2 groups, namely group with strong and weak decrease rate for low-anisotropy (FeCo, La0.3Sr0.7MnO3, MnFe2O4, g-Fe2O3), and high-anisotropy (CoFe2O4 and FePt) materials, respectively.

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Concentration-dependent oscillation of specific loss power in magnetic nanofluid hyperthermia

Scientific Reports ◽

10.1038/s41598-020-79871-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Ji-wook Kim ◽

Jie Wang ◽

Hyungsub Kim ◽

Seongtae Bae

Keyword(s):

Magnetic Dipole ◽

Critical Role ◽

Dipole Interaction ◽

Superparamagnetic Nanoparticles ◽

Physical Reason ◽

Strong Concentration ◽

Magnetic Nanofluid ◽

Specific Loss ◽

Specific Loss Power ◽

Magnetic Nanofluid Hyperthermia

AbstractMagnetic dipole coupling between the colloidal superparamagnetic nanoparticles (SPNPs) depending on the concentration has been paid significant attention due to its critical role in characterizing the Specific Loss Power (SLP) in magnetic nanofluid hyperthermia (MNFH). However, despite immense efforts, the physical mechanism of concentration-dependent SLP change behavior is still poorly understood and some contradictory results have been recently reported. Here, we first report that the SLP of SPNP MNFH agent shows strong concentration-dependent oscillation behavior. According to the experimentally and theoretically analyzed results, the energy competition among the magnetic dipole interaction energy, magnetic potential energy, and exchange energy, was revealed as the main physical reason for the oscillation behavior. Empirically demonstrated new finding and physically established model on the concentration-dependent SLP oscillation behavior is expected to provide biomedically crucial information in determining the critical dose of an agent for clinically safe and highly efficient MNFH in cancer clinics.

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Magnetic Nanoparticle Hyperthermia: Maximizing Specific Loss Power for Magnetic Hyperthermia by Hard-Soft Mixed Ferrites (Small 29/2018)

Small ◽

10.1002/smll.201870133 ◽

2018 ◽

Vol 14 (29) ◽

pp. 1870133 ◽

Cited By ~ 2

Author(s):

Shuli He ◽

Hongwang Zhang ◽

Yihao Liu ◽

Fan Sun ◽

Xiang Yu ◽

...

Keyword(s):

Magnetic Nanoparticle ◽

Magnetic Hyperthermia ◽

Specific Loss ◽

Mixed Ferrites ◽

Specific Loss Power ◽

Magnetic Nanoparticle Hyperthermia

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Role of zinc substitution in magnetic hyperthermia properties of magnetite nanoparticles: interplay between intrinsic properties and dipolar interactions

Scientific Reports ◽

10.1038/s41598-019-54250-7 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 6

Author(s):

Yaser Hadadian ◽

Ana Paula Ramos ◽

Theo Z. Pavan

Keyword(s):

Magnetic Nanoparticles ◽

Magnetite Nanoparticles ◽

Linear Response Theory ◽

Magnetic Hyperthermia ◽

Superior Performance ◽

Dipolar Interactions ◽

Intrinsic Properties ◽

Specific Loss ◽

Heating Efficiency ◽

Specific Loss Power

AbstractOptimizing the intrinsic properties of magnetic nanoparticles for magnetic hyperthermia is of considerable concern. In addition, the heating efficiency of the nanoparticles can be substantially influenced by dipolar interactions. Since adequate control of the intrinsic properties of magnetic nanoparticles is not straightforward, experimentally studying the complex interplay between these properties and dipolar interactions affecting the specific loss power can be challenging. Substituting zinc in magnetite structure is considered as an elegant approach to tune its properties. Here, we present experimental and numerical simulation results of magnetic hyperthermia studies using a series of zinc-substituted magnetite nanoparticles (ZnxFe1-xFe2O4, x = 0.0, 0.1, 0.2, 0.3 and 0.4). All experiments were conducted in linear regime and the results were inferred based on the numerical simulations conducted in the framework of the linear response theory. The results showed that depending on the nanoparticles intrinsic properties, interparticle interactions can have different effects on the specific loss power. When dipolar interactions were strong enough to affect the heating efficiency, the parameter σ = KeffV/kBT (Keff is the effective anisotropy and V the volume of the particles) determined the type of the effect. Finally, the sample x = 0.1 showed a superior performance with a relatively high intrinsic loss power 5.4 nHm2kg−1.

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