Canting of the Magnetic Moments on the Octahedral Site of an Iron Oxide Garnet in Response to Diamagnetic Cation Substitution

2021 ◽  
Vol 60 (9) ◽  
pp. 6249-6254
Author(s):  
JoAnna Milam-Guerrero ◽  
Michelle Zheng ◽  
Nicole R. Spence ◽  
Stuart Calder ◽  
Saul Lapidus ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Octahedral Site ◽  
Magnetic Moments ◽  
Cation Substitution

scholarly journals Imaging Constructs: The Rise of Iron Oxide Nanoparticles

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3437
Author(s):  
Bianca Elena-Beatrice Crețu ◽  
Gianina Dodi ◽  
Amin Shavandi ◽  
Ioannis Gardikiotis ◽  
Ionela Lăcrămioara Șerban ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Magnetic Moments ◽  
Quantitative Imaging ◽  
Oxide Nanoparticles ◽  
Imaging Probes ◽  
Effective System ◽  
Important Challenge ◽  
Metal Oxide Nanomaterials ◽  
Clinical Potential

Over the last decade, an important challenge in nanomedicine imaging has been the work to design multifunctional agents that can be detected by single and/or multimodal techniques. Among the broad spectrum of nanoscale materials being investigated for imaging use, iron oxide nanoparticles have gained significant attention due to their intrinsic magnetic properties, low toxicity, large magnetic moments, superparamagnetic behaviour and large surface area—the latter being a particular advantage in its conjunction with specific moieties, dye molecules, and imaging probes. Tracers-based nanoparticles are promising candidates, since they combine synergistic advantages for non-invasive, highly sensitive, high-resolution, and quantitative imaging on different modalities. This study represents an overview of current advancements in magnetic materials with clinical potential that will hopefully provide an effective system for diagnosis in the near future. Further exploration is still needed to reveal their potential as promising candidates from simple functionalization of metal oxide nanomaterials up to medical imaging.

scholarly journals Signature of antiphase boundaries in iron oxide nanoparticles

2021 ◽  
Vol 54 (6) ◽  
Author(s):  
Tobias Köhler ◽  
Artem Feoktystov ◽  
Oleg Petracic ◽  
Nileena Nandakumaran ◽  
Antonio Cervellino ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Powder Diffraction ◽  
Magnetic Moments ◽  
Reference Value ◽  
Oxide Nanoparticles ◽  
Planar Lattice ◽  
Antiphase Boundaries ◽  
Diffraction Patterns ◽  
The Fourier Transform

Iron oxide nanoparticles find a wide variety of applications, including targeted drug delivery and hyperthermia in advanced cancer treatment methods. An important property of these particles is their maximum net magnetization, which has been repeatedly reported to be drastically lower than the bulk reference value. Previous studies have shown that planar lattice defects known as antiphase boundaries (APBs) have an important influence on the particle magnetization. The influence of APBs on the atomic spin structure of nanoparticles with the γ-Fe2O3 composition is examined via Monte Carlo simulations, explicitly considering dipole–dipole interactions between the magnetic moments that have previously only been approximated. For a single APB passing through the particle centre, a reduction in the magnetization of 3.9% (for 9 nm particles) to 7.9% (for 5 nm particles) is found in saturation fields of 1.5 T compared with a particle without this defect. Additionally, on the basis of Debye scattering equation simulations, the influence of APBs on X-ray powder diffraction patterns is shown. The Fourier transform of the APB peak profile is developed to be used in a whole powder pattern modelling approach to determine the presence of APBs and quantify them by fits to powder diffraction patterns. This is demonstrated on experimental data, where it could be shown that the number of APBs is related to the observed reduction in magnetization.

Synthesis and characterisation of iron oxide (Fe3O4) ferrofluid nanoparticles coated by poly (vinyl butyral) with microsphere

2021 ◽  
Vol 13 ◽  
Author(s):  
Sharanabasava V. Ganachari ◽  
Nagaraj R. Banapurmath ◽  
Jayachandra S. Yaradoddi ◽  
Veerabhadragouda B. Patil ◽  
Akshata Yavagal ◽  
...  
Keyword(s):  
Shear Stress ◽  
Iron Oxide ◽  
Magnetic Moments ◽  
Polyvinyl Butyral ◽  
Atomic Size ◽  
Shear Rates ◽  
Characterization Studies ◽  
Magneto Rheological ◽  
Co Precipitation ◽  
Vinyl Butyral

Objective: Synthesis of magnetic nano Iron oxide (Fe3O4) ferrofluid nanoparticles using chemical methods and its characterization studies Method: Iron oxide (Fe3O4) ferrofluid nanoparticles is synthesized by using the chemical co-precipitation technique, ferric and ferrous salts in the alkaline medium, which is known as Reimer’s procedure. Results: Nano iron oxide (Fe3O4) particles have different magnetic properties and different magnetic moments, differentiating macroscopic iron oxide in suspended particles. The ratio of surface to volume increases along with the decrease in atomic size so that the surface properties are essential for using any nano-material. Prepared Fe3O4 nanoparticles were coated with oleic acid (C18H34O2) and polyvinyl butyral((C8H14O2)n), further characterized by Materials characterization techniques (SEM, XRD and FTIR). Magneto-rheological (MR) fluid has been one of the interesting studies the shear stress of PVB coated nano iron with microsphere has approximately the same as of PVB coated nano iron but shows very high shear stress withstanding capacity at 650 s-1 shear rates. Conclusion: The permanence of the magnetic colloidal depends on the thermal contribution and the balance between attractive and repulsive interactions.

TEM observation of iron oxide pillars in montmorillonite

1990 ◽  
Vol 48 (4) ◽  
pp. 882-883
Author(s):  
H. Mori ◽  
Y. Murata ◽  
H. Yoneyama ◽  
H. Fujita
Keyword(s):  
Aqueous Solution ◽  
Iron Oxide ◽  
Fine Particles ◽  
Aqueous Suspension ◽  
Volume Ratio ◽  
Exchange Capacity ◽  
Nano Composites ◽  
Pillared Montmorillonite ◽  
Topographic Features ◽  
Transmission Electron

Recently, a new sort of nano-composites has been prepared by incorporating such fine particles as metal oxide microcrystallites and organic polymers into the interlayer space of montmorillonite. Owing to their extremely large specific surface area, the nano-composites are finding wide application[1∼3]. However, the topographic features of the microstructures have not been elucidated as yet In the present work, the microstructures of iron oxide-pillared montmorillonite have been investigated by high-resolution transmission electron microscopy.Iron oxide-pillared montmorillonite was prepared through the procedure essentially the same as that reported by Yamanaka et al. Firstly, 0.125 M aqueous solution of trinuclear acetato-hydroxo iron(III) nitrate, [Fe3(OCOCH3)7 OH.2H2O]NO3, was prepared and then the solution was mixed with an aqueous suspension of 1 wt% clay by continuously stirring at 308 K. The final volume ratio of the latter aqueous solution to the former was 0.4. The clay used was sodium montmorillonite (Kunimine Industrial Co.), having a cation exchange capacity of 100 mequiv/100g. The montmorillonite in the mixed suspension was then centrifuged, followed by washing with deionized water. The washed samples were spread on glass plates, air dried, and then annealed at 673 K for 72 ks in air. The resultant film products were approximately 20 μm in thickness and brown in color.

TARGETING CYCLIN B1 WITH ANTISENSE OLIGONUCLETOTIDES- COATED SUPERPARAMAGNETIC IRON OXIDE NANOPARTICLES

2018 ◽  
Vol 6 (10) ◽  
Author(s):  
Hosam Zaghloul ◽  
Doaa A. Shahin ◽  
Ibrahim El- Dosoky ◽  
Mahmoud E. El-awady ◽  
Fardous F. El-Senduny ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Cellular Uptake ◽  
Superparamagnetic Iron Oxide ◽  
Cyclin B1 ◽  
Superparamagnetic Iron Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Mcf7 Cells ◽  
M Phase ◽  
The Impact

Antisense oligonucleotides (ASO) represent an attractive trend as specific targeting molecules but sustain poor cellular uptake meanwhile superparamagnetic iron oxide nanoparticles (SPIONs) offer stability of ASO and improved cellular uptake. In the present work we aimed to functionalize SPIONs with ASO targeting the mRNA of Cyclin B1 which represents a potential cancer target and to explore its anticancer activity. For that purpose, four different SPIONs-ASO conjugates, S-M (1–4), were designated depending on the sequence of ASO and constructed by crosslinking carboxylated SPIONs to amino labeled ASO. The impact of S-M (1–4) on the level of Cyclin B1, cell cycle, ROS and viability of the cells were assessed by flowcytometry. The results showed that S-M3 and S-M4 reduced the level of Cyclin B1 by 35 and 36%, respectively. As a consequence to downregulation of Cyclin B1, MCF7 cells were shown to be arrested at G2/M phase (60.7%). S-M (1–4) led to the induction of ROS formation in comparison to the untreated control cells. Furthermore, S-M (1–4) resulted in an increase in dead cells compared to the untreated cells and SPIONs-treated cells. In conclusion, targeting Cyclin B1 with ASO-coated SPIONs may represent a specific biocompatible anticancer strategy.

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