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Photo-switching of magnetization in iron nanoparticles

We report the theoretical study of the light-induced switching of magnetization in core–shell nanoparticles. The core of the nanoparticle is made of iron (Fe) coated with the shell of azobenzene. Azobenzene is a photochromic material with reversible trans–cis photoisomerization upon irradiation by UV and vis 2014 Journal of Materials Chemistry C Hot Articles

Mechanism of magnetization reduction in iron oxide

reduction in magnetization in the particle core.27,29 Mössbauer spectroscopy and magnetometry measurements performed on iron oxide nanoparticles with diameters of 15 nm suggested the lack of a magnetically dead layer.30 Iron oxide nanoparticles with overall size of 7.4 nm were shown to be homogeneously magnetized with no significant spin dis-

Effect of surface modification on magnetization of iron

Magnetic iron oxide nanoparticles have numerous applications in the biomedical field, some more mature, such as contrast agents in magnetic resonance imaging (MRI), and some emerging, such as heating agents in hyperthermia for cancer therapy. In all of these applications, the magnetic particles are

Reversible Photo‐Switching of the Magnetization of Iron

2004-11-17  Reversible Photo‐Switching of the Magnetization of Iron Oxide Nanoparticles at Room Temperature † Rie Mikami Department of Chemistry, Faculty of Science and Technology, Keio University, 3‐14‐1 Hiyoshi, Yokohama 223‐8522, Japan, (+81) 45‐566‐1697

Synthesis of iron oxides nanoparticles with very high

2017-11-5  In the present work, multi-phases iron oxide nanoparticles with very high magnetization saturation (Ms) were obtained via the potentiostatic method. The bath of deposition is analogs to previous work [33],[34],but with different available and cheaper iron salt precursor of FeCl 3 .

A simple way to obtain high saturation magnetization for

2016-7-1  Saturation magnetization of the superparamagnetic iron oxide nanoparticles is optimized by a simple method. • Characterizations of the nanoparticles are performed by XRD, FTIR, SAED, TEM, VSM and PPMS. • The highest M s was obtained as 69.83 emu/g for 7.0±2.2 nm superparamagnetic iron oxide nanoparticles.

A promising electrodeposited iron oxide nanoparticles of

2018-12-1  Magnetization measurements for the electrodeposited iron oxide nanoparticles samples at different deposition potentials; − 1.15, − 1.20, − 1.25 and − 1.30 V are illustrated in Fig. 6. The magnetization curves have been recorded at room temperature in the applied magnetic field sweeping from − 8.5 to + 8.5 kOe.

Particle size determination from magnetization curves in

2020-4-15  There is even a decrease in magnetization from sample GOAc3 to GOAc4, unexpected from the typical tendency of saturation magnetization of iron oxide nanoparticles to be smaller for smaller particles due to spin canting effects . In addition to particle diameter, the other features changing the iron oxide content are flake coverage and degree of

Influence of Viscosity on Dynamic Magnetization of

2019-2-2  In this work, we show that the viscosity of carrier liquid affects the dynamic magnetization of thermally blocked multi-core iron oxide nanoparticles. The core size of the nanoparticles was determined from the magnetization curve measured by a specially developed high-Tc SQUID magnetometer and calculated to be 11.7 nm. Using an AC magnetometer developed based on induction coils, the

Size Effects in Iron Borate FeBO3 Nanoparticles

2021-8-24  Such broadening in the case of nanoparticles can be explained by a significant increase in the magnetic anisotropy energy K in iron borate nanoparticles as compared to polycrystals. According to our estimates, K = (804.2 ± 1.2) × 10 3 and (2.770 ± 0.048) × 10 3 erg/cm 3 for nanoparticles and polycrystalline FeBO 3, respectively. Fig. 4.

Reversible Photo‐Switching of the Magnetization of Iron

2004-11-17  Reversible Photo‐Switching of the Magnetization of Iron Oxide Nanoparticles at Room Temperature † Rie Mikami Department of Chemistry, Faculty of Science and Technology, Keio University, 3‐14‐1 Hiyoshi, Yokohama 223‐8522, Japan, (+81) 45‐566‐1697

Magnetization reversal of iron nanoparticles studied by

Magnetization of an array of 16 elongated iron nanoparticles with diameter of ∼7 nm and height of ∼100 nm has been studied with a submicron semiconductor Hall magnetometer. Details of the magnetization hysteresis curves and the angular dependence of switching fields are examined. The results indicate that the magnetization reversal in these cylindrical nanoparticles cannot be described

Effect of surface modification on magnetization of iron

2012-8-24  In addition to these, in-house prepared iron oxide nanoparticles coated with oleic acid and suspended in heptane and hexane were also investigated. The saturation magnetization obtained from vibrating sample magnetometry (VSM) measurements was used to determine the effective concentration of magnetic phase in all samples.

(PDF) Ultrasmall iron nanoparticles: Effect of size

These nanoparticles display a magnetization of 1.13 μB per iron atom, which is more than two times smaller than the bulk value [Show full abstract] with the same composition. No surface

BJNANO Structural and magnetic properties of iron

The effects of iron oxidation and the following phase transformations of iron oxides have a greater impact on the decrease of magnetization in the case of iron nanoparticles. It is related to the fact that Fe NPs have a larger surface area exposed to the atmosphere than Fe NWs.

Size Effects in Iron Borate FeBO3 Nanoparticles

2021-8-24  Such broadening in the case of nanoparticles can be explained by a significant increase in the magnetic anisotropy energy K in iron borate nanoparticles as compared to polycrystals. According to our estimates, K = (804.2 ± 1.2) × 10 3 and (2.770 ± 0.048) × 10 3 erg/cm 3 for nanoparticles and polycrystalline FeBO 3, respectively. Fig. 4.

Versatile iron cobalt nanoparticles for theranostics

2020-3-12  The metallic core of a nanoparticle, and thus its high magnetization, can also be preserved by the addition of iron carbonyl and its subsequent decomposition on iron nanoparticle seeds 8. The

Influence of experimental parameters on iron oxide

2018-2-27  The synthesis of iron oxide nanoparticles with a high relaxivity and a high saturation magnetization can be obtained with a short reaction time at high temperature. Moreover, the influence of surfactant concentrations determines the optimal value in order to produce iron oxide nanoparticles with a narrow size distribution.

Origin of reduced magnetization and domain formation in

2017-4-10  The experiments compared 12–14 nm diameter iron oxide nanoparticles synthesized by three well-established methods that were pioneered by the groups of

Embracing Defects and Disorder in Magnetic Nanoparticles

2021-2-15  [174,175 ] Doping in iron oxide nanoparticles has traditionally been mainly used to reduce compensating magnetic couplings and improve magnetization, as in the case of Zn 2+ in iron oxide nanoparticles. We envision the opportunity of inducing other defects and thus tailoring magnetic anisotropy of nanoparticles by defect‐induced distortion

Magnetization reversal of iron nanoparticles studied by

A submicron semiconductor Hall magnetometer was used to study magnetization of an array of 16 elongated iron nanoparticles with diameter of ∼7 nm and height of ∼100 nm. The magnetization hysteresis curves and the angular dependence of switching fields were also examined.

Magnetization response spectroscopy of

2019-5-18  Magnetization response spectroscopy of superparamagnetic nanoparticles for It measures the spatial distribution of superparamagnetic iron oxide nanoparticles (SPIOs). MPI is a quantitative imaging modality, providing high sensitivity and sub-millimetre spatial resolution [2]. Furthermore, the acquisition time is short,

BJNANO Structural and magnetic properties of iron

The effects of iron oxidation and the following phase transformations of iron oxides have a greater impact on the decrease of magnetization in the case of iron nanoparticles. It is related to the fact that Fe NPs have a larger surface area exposed to the atmosphere than Fe NWs.

(PDF) Ultrasmall iron nanoparticles: Effect of size

These nanoparticles display a magnetization of 1.13 μB per iron atom, which is more than two times smaller than the bulk value [Show full abstract] with the same composition. No surface

Magnetization Reversal of Individual Cylindrical Iron

The magnetization dynamics of ferromagnetic nanowires has recently attracted much attention [1]. So far, most measurements on individual nanowires have been done on electrodeposited Ni or Co wires, in which there are competing energy scales of comparable magnitude. On the other hand, Fe is dominated by shape anisotropy, yet no work has been reported on individual, isolated Fe nanowires.

Biogenic Fabrication of Iron/Iron Oxide Nanoparticles

2017-8-23  Magnetization of nanoparticle is therefore essential. It is of prime importance that the nanoparticles should be se-lected from among the transition metal ions which are highly magnetic in nature. Nonfunctionalized iron oxide nanoparticles have been used for labeling leucocytes, lymphocytes, etc. [86–88]. Cellular uptake of iron oxide

Influence of experimental parameters on iron oxide

2018-2-27  The synthesis of iron oxide nanoparticles with a high relaxivity and a high saturation magnetization can be obtained with a short reaction time at high temperature. Moreover, the influence of surfactant concentrations determines the optimal value in order to produce iron oxide nanoparticles with a narrow size distribution.

Study of the magnetic properties of Mn‐doped iron

2021-1-20  In this study, iron titanate (FT) and manganese-doped iron titanate (MFT) nanoparticles were synthesised from a natural mineral, ilmenite ore, using a simple and effective method. X-ray diffraction analysis confirmed the reduction of crystallite size from 56 to 29 nm with an increase in Mn doping concentration from 0% to 2%.

Embracing Defects and Disorder in Magnetic Nanoparticles

2021-2-15  [174,175 ] Doping in iron oxide nanoparticles has traditionally been mainly used to reduce compensating magnetic couplings and improve magnetization, as in the case of Zn 2+ in iron oxide nanoparticles. We envision the opportunity of inducing other defects and thus tailoring magnetic anisotropy of nanoparticles by defect‐induced distortion

Origin of reduced magnetization and domain formation in

2017-4-10  The experiments compared 12–14 nm diameter iron oxide nanoparticles synthesized by three well-established methods that were pioneered by the groups of