Size-Dependent Crystalline and Magnetic Properties of 5–100 nm Fe ₃ O ₄ Nanoparticles: Superparamagnetism, Verwey Transition, and FeO–Fe ₃ O ₄ Core–Shell Formation

Klomp, Shelby; Walker, Colby; Christiansen, Mason; Newbold, Brittni; Griner, Dalton; Cai, Yanping; Minson, P.; Farrer, Jeffrey K.; Smith, Stacey J.; Campbell, Branton J.; Harrison, Roger G.; Chesnel, Karine

doi:10.1109/tmag.2020.3018154

Cited by 7 publications

(8 citation statements)

References 39 publications

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“…The narrowness of the peak exhibited by the ZFC curve reflects the narrowness of the particle size distribution. This result is consistent with FC/ZFC measurements on previous batches of 5 nm NPs prepared using the same method [12,23]. The proper way to estimate the blocking temperature T B from magnetometry data has been subject to debate in recent years [11,26].…”

Section: Nm Nanoparticles: Tem and Magnetometrysupporting

confidence: 87%

“…Two samples with average particle sizes of approximately 5 nm and 20 nm were studied. As established in previous studies [12,23], we find that the blocking temperature T B increases significantly as the particle size is increased from 5 nm to 20 nm. The magnetometry results provide insight into the drastic dependence of the blocking temperature on particle size and on how the particle size distribution affects the extent of the blocking transition, but quantitative information about the size distribution dependence of the blocking transition requires complex modeling [11].…”

Section: Introductionsupporting

confidence: 87%

“…The magnitude of M s may be estimated by using the volume of each NP and the density of magnetic ions in the material. Based on previous crystallographic studies of these samples [12], the cubic lattice parameter is 8.35 Å and the atomic density is about 13.7 Fe 3 O 4 units per nm 3 . Accounting for combined spins carried by the Fe 2+ and Fe 3+ ions in the spinel structure [18], the saturated magnetization density is about 55 µ B /nm 3 .…”

Section: Nm Nanoparticles: Tem and Magnetometrymentioning

confidence: 99%

“…This transition has been previously observed in FC/ZFC curves collected on larger Fe 3 O 4 NPs. One study on 50-100 nm NPs shows the occurrence of a clear peak at 125 K [12]. Another study shows a kink in the FC/ZFC curves located at lower temperatures, 16 K for 50 nm NPs and 98 K for 150 nm NPs [5].…”

Section: Nm Nanoparticles: Tem and Magnetometrymentioning

confidence: 99%

“…Although much experimental and theoretical work has been performed to understand superparamagnetism and the blocking transition [8][9][10], many details relating to these behaviors remain unclear. Among others, these behaviors include the precise manner in which the the blocking transition proceeds throughout the sample, and how this affects experimental data [11]; the influence of the structure and morphology across varying length scales [7,12]; and even the estimation of microscopic parameters such as the nanoparticle spin flip activation energy and fluctuation time [13]. There is increasing recognition that a more complete understanding is most likely to be obtained by attacking the problem with a variety of complementary techniques, such as magnetometry [9], Mössbauer spectroscopy [14], electronic microscopy [15] and holography [16], neutron scattering [17], x-ray magnetic spectroscopy [18], or x-ray magnetic scattering [19].…”

Section: Introductionmentioning

confidence: 99%

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Superparamagnetic dynamics and blocking transition in Fe$_3$O$_4$ nanoparticles probed by vibrating sample magnetometry and muon spin relaxation

Frandsen,

Read,

Stevens

et al. 2021

Preprint

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The magnetic properties of Fe3O4 nanoparticle assemblies have been investigated in detail through a combination of vibrating sample magnetometry and muon spin relaxation (µSR) techniques. Two samples with average particle sizes of 5 nm and 20 nm, respectively, were studied. For both samples, the magnetometry and µSR results exhibit clear signatures of the superparmagnetic state at high temperature and the magnetically blocked state at low temperature. The µSR data demonstrate that the transition from the superparamagnetic to the blocked state occurs gradually throughout the sample volume over a broad temperature range due to the finite particle size distribution of each sample. The transition occurs between approximately 3 K and 45 K for the 5 nm sample and 150 K and 300 K for the 20 nm sample. The magnetometry and µSR data are further analyzed to yield estimates of microscopic magnetic parameters including the nanoparticle spin-flip activation energy EA, magnetic anisotropy K, and intrinsic nanoparticle spin reversal attempt time τ0. These results highlight the complementary information about magnetic nanoparticles that can be obtained by bulk magnetic probes such as magnetometry and local magnetic probes such as µSR.

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Section: Nm Nanoparticles: Tem and Magnetometrysupporting

confidence: 87%

Section: Introductionsupporting

confidence: 87%

Section: Nm Nanoparticles: Tem and Magnetometrymentioning

confidence: 99%

Section: Nm Nanoparticles: Tem and Magnetometrymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Superparamagnetic dynamics and blocking transition in Fe$_3$O$_4$ nanoparticles probed by vibrating sample magnetometry and muon spin relaxation

Frandsen,

Read,

Stevens

et al. 2021

Preprint

Self Cite

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Composite materials based on a ceramic matrix of polycarbosilane and iron-containing nanoparticles

Yurkov

Pankratov

Koksharov

et al. 2022

Ceramics International

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Bacterial Binding to Polydopamine-Coated Magnetic Nanoparticles

Houser,

Camacho,

Bryner

et al. 2024

ACS Appl. Mater. Interfaces

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In medical infections such as blood sepsis and in food quality control, fast and accurate bacteria analysis is required. Using magnetic nanoparticles (MNPs) for bacterial capture and concentration is very promising for rapid analysis. When MNPs are functionalized with the proper surface chemistry, they have the ability to bind to bacteria and aid in the removal and concentration of bacteria from a sample for further analysis. This study introduces a novel approach for bacterial concentration using polydopamine (pDA), a highly adhesive polymer often purported to create antibacterial and antibiofouling coatings on medical devices. Although pDA has been generally studied for its ability to coat surfaces and reduce biofilm growth, we have found that when coated on magnetic nanoclusters (MNCs), more specifically iron oxide nanoclusters, it effectively binds to and can remove from suspension some types of bacteria. This study investigated the binding of pDA-coated MNCs (pDA-MNCs) to various Gram-negative and Gram-positive bacteria, including Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and several E. coli strains. MNCs were successfully coated with pDA, and these functionalized MNCs bound a wide variety of bacterial strains. The efficiency of removing bacteria from a suspension can range from 0.99 for S. aureus to 0.01 for an E. coli strain. Such strong capture and differential capture have important applications in collecting bacteria from dilute samples found in medical diagnostics, food and water quality monitoring, and other industries.

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Size-Dependent Crystalline and Magnetic Properties of 5–100 nm Fe ₃ O ₄ Nanoparticles: Superparamagnetism, Verwey Transition, and FeO–Fe ₃ O ₄ Core–Shell Formation

Cited by 7 publications

References 39 publications

Superparamagnetic dynamics and blocking transition in Fe$_3$O$_4$ nanoparticles probed by vibrating sample magnetometry and muon spin relaxation

Superparamagnetic dynamics and blocking transition in Fe$_3$O$_4$ nanoparticles probed by vibrating sample magnetometry and muon spin relaxation

Composite materials based on a ceramic matrix of polycarbosilane and iron-containing nanoparticles

Bacterial Binding to Polydopamine-Coated Magnetic Nanoparticles

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