scholarly journals Magnetic Properties of Bi-Magnetic Core/Shell Nanoparticles: The Case of Thin Shells

2021 ◽  
Vol 7 (11) ◽  
pp. 146
Author(s):  
Alexander Omelyanchik ◽  
Silvia Villa ◽  
Gurvinder Singh ◽  
Valeria Rodionova ◽  
Sara Laureti ◽  
...  
Keyword(s):  
Single Phase ◽  
Magnetic Core ◽  
Core Shell ◽  
Interparticle Interactions ◽  
Shell Nanoparticles ◽  
Transmission Electron ◽  
Temperature Decomposition ◽  
Metal Acetylacetonate ◽  
Magnetically Hard ◽  
Core Shell Nanoparticles

Bi-magnetic core/shell nanoparticles were synthesized by a two-step high-temperature decomposition method of metal acetylacetonate salts. Transmission electron microscopy confirmed the formation of an ultrathin shell (~0.6 nm) of NiO and NiFe2O4 around the magnetically hard 8 nm CoFe2O4 core nanoparticle. Magnetization measurements showed an increase in the coercivity of the single-phase CoFe2O4 seed nanoparticles from ~1.2 T to ~1.5 T and to ~2.0 T for CoFe2O4/NiFe2O4 and CoFe2O4/NiO, respectively. The NiFe2O4 shell also increases the magnetic volume of particles and the dipolar interparticle interactions. In contrast, the NiO shell prevents such interactions and keeps the magnetic volume almost unchanged.

scholarly journals Interplay between inter- and intraparticle interactions in bi-magnetic core/shell nanoparticles

2021 ◽  
Author(s):  
Alexander Omelyanchik ◽  
Silvia Villa ◽  
Marianna Vasilakaki ◽  
Gurvinder Singh ◽  
Anna Maria Ferretti ◽  
...  
Keyword(s):  
Cobalt Ferrite ◽  
Magnetic Core ◽  
Shell Morphology ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Synthesis Strategy ◽  
Two Systems ◽  
Magnetically Hard ◽  
Core Shell Nanoparticles ◽  
Soft Nanoparticles

The synthesis strategy and magnetic characterisation of two systems consisting of nanoparticles with core/shell morphology are presented: an assembly of hard/soft nanoparticles with cores consisting of magnetically hard cobalt ferrite...

scholarly journals Hybrid Nanoelectronic-magnetic Device with Magnetoresistive Effect for logic integrated platforms in Spintronics

2019 ◽  
Author(s):  
Ovidiu Crisan ◽  
Alina Daniela Crisan ◽  
Catalin Romeo Luculescu
Keyword(s):  
Magnetic Core ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Magnetic Device ◽  
Hybrid Device ◽  
Optical Scanning ◽  
Nanosized Materials ◽  
Electron Microscopies ◽  
Transmission Electron ◽  
Core Shell Nanoparticles

We propose a concept of hybrid nanoelectronic-magnetic device for logic integrated platforms made of magnetic core-shell nanoparticles deposited onto prepatterned Si (111) substrate with basic logic circuitry made of metallic conductive lines. The synthesis of magnetic material and the creation of nanoelectronic prepatterned interdigitated die is reported and its capabilities are demonstrated in terms of magnetotransport properties. The laser pyrolysis method is employed in order to synthesize magnetic core-shell Fe / FeC nanoparticles with sizes between 12 – 15 nm. E-beam lithography has been used in order to design and execute two different layouts of interdigitated die, prepatterned with logic capacity, one with two pads and 50 microns thick conductive metallic lines, another one with 4 pads and parallel 5 microns thick conductive lines separated by 5 microns thick spacer. The as-obtained structures are morphologically characterized by means of optical, scanning and transmission electron microscopies. As-synthesized core-shell nanoparticles have been magnetically characterized inasmuch as the hybrid device obtained by depositing centrifugated and dispersed core-shell nanoparticles from liquid carrier solutions. For the first time, a significant giant magnetoresistive (GMR) effect has been observed and measured for the hybrid architectured device made of Fe / FeC nanosized materials on pre-patterned interdigitated die. A ∆R/R of 8% at 4.2 K has been measured from conductivity-in-plane electron transport measurements. This opens possibilities for the use of such devices as arrays of nanosensors and in spintronic applications.

scholarly journals Plasma-assisted synthesis and high-resolution characterization of anisotropic elemental and bimetallic core–shell magnetic nanoparticles

2014 ◽  
Vol 5 ◽  
pp. 466-475 ◽  
Author(s):  
M Hennes ◽  
A Lotnyk ◽  
S G Mayr
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Magnetic Core ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Gas Condensation ◽  
Pulsed Dc ◽  
Transmission Electron ◽  
Core Shell Nanoparticles ◽  
Kinetic Gas Theory

Magnetically anisotropic as well as magnetic core–shell nanoparticles (CS-NPs) with controllable properties are highly desirable in a broad range of applications. With this background, a setup for the synthesis of heterostructured magnetic core–shell nanoparticles, which relies on (optionally pulsed) DC plasma gas condensation has been developed. We demonstrate the synthesis of elemental nickel nanoparticles with highly tunable sizes and shapes and Ni@Cu CS-NPs with an average shell thickness of 10 nm as determined with scanning electron microscopy, high-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy measurements. An analytical model that relies on classical kinetic gas theory is used to describe the deposition of Cu shell atoms on top of existing Ni cores. Its predictive power and possible implications for the growth of heterostructured NP in gas condensation processes are discussed.

Fe3O4@ZrO2 magnetic nanoparticles as a new electrode material for sensitive determination of organophosphorus agents

2015 ◽  
Vol 7 (12) ◽  
pp. 5053-5059 ◽  
Author(s):  
Na-Na Li ◽  
Tian-Fang Kang ◽  
Jing-Jing Zhang ◽  
Li-Ping Lu ◽  
Shui-Yuan Cheng
Keyword(s):  
Photoelectron Spectroscopy ◽  
Magnetic Core ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Shell Nanoparticles ◽  
X Ray ◽  
Transmission Electron ◽  
Sensitive Determination ◽  
Core Shell Nanoparticles

In this study, Fe3O4@ZrO2 magnetic core–shell nanoparticles (NPs) were synthesized and were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS).

scholarly journals Fabrication of copper(II)-coated magnetic core-shell nanoparticles Fe3O4@SiO2-2-aminobenzohydrazide and investigation of its catalytic application in the synthesis of 1,2,3-triazole compounds

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
H. Rajabi-Moghaddam ◽  
M. R. Naimi-Jamal ◽  
M. Tajbakhsh
Keyword(s):  
High Efficiency ◽  
Click Reaction ◽  
Magnetic Core ◽  
Core Shell ◽  
Isatoic Anhydride ◽  
Shell Nanoparticles ◽  
Triazole Derivatives ◽  
Catalytic Application ◽  
Ft Ir ◽  
Core Shell Nanoparticles

AbstractIn the present work, an attempt has been made to synthesize the 1,2,3-triazole derivatives resulting from the click reaction, in a mild and green environment using the new copper(II)-coated magnetic core–shell nanoparticles Fe3O4@SiO2 modified by isatoic anhydride. The structure of the catalyst has been determined by XRD, FE-SEM, TGA, VSM, EDS, and FT-IR analyzes. The high efficiency and the ability to be recovered and reused for at least up to 6 consecutive runs are some superior properties of the catalyst.

scholarly journals Multifunktionale bakterielle Nanomagnete für Biotechnologie und Medizin

BIOspektrum ◽  
2021 ◽  
Vol 27 (4) ◽  
pp. 442-444
Author(s):  
Frank Mickoleit ◽  
Sabine Rosenfeldt ◽  
Anna S. Schenk ◽  
Dirk Schüler ◽  
René Uebe
Keyword(s):  
Particle Production ◽  
Magnetotactic Bacteria ◽  
Magnetic Core ◽  
High Yield ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Magnetospirillum Gryphiswaldense ◽  
Core Shell Nanoparticles ◽  
Genetic Toolkit ◽  
The Way

AbstractBacterial magnetosomes represent magnetic core-shell nanoparticles biomineralized by magnetotactic bacteria like Magnetospirillum gryphiswaldense. The establishment of fermentation regimes for high-yield particle production, standardized isolation procedures as well as the development of a genetic toolkit for the generation of “tailored” particles might soon pave the way for the application of engineered magnetosomes in the biomedical and biotechnological field.

scholarly journals Novel magnetic core-shell nanoparticles for the removal of polychlorinated biphenyls from contaminated water sources

2019 ◽  
Vol 223 ◽  
pp. 68-74 ◽  
Author(s):  
Angela M. Gutierrez ◽  
Rohit Bhandari ◽  
Jiaying Weng ◽  
Arnold Stromberg ◽  
Thomas D. Dziubla ◽  
...  
Keyword(s):  
Polychlorinated Biphenyls ◽  
Magnetic Core ◽  
Water Sources ◽  
Core Shell ◽  
Contaminated Water ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles

Monodisperse Fe3O4/Fe Core/Shell Nanoparticles with Enhanced Magnetic Property

2011 ◽  
Vol 306-307 ◽  
pp. 410-415
Author(s):  
Li Sun ◽  
Fu Tian Liu ◽  
Qi Hui Jiang ◽  
Xiu Xiu Chen ◽  
Ping Yang
Keyword(s):  
Average Diameter ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Shell Nanoparticles ◽  
X Ray ◽  
Transmission Electron ◽  
Shell Particles ◽  
Core Shell Nanoparticles

Core/shell type nanoparticles with an average diameter of 20nm were synthesized by chemical precipitation method. Firstly, Monodisperse Fe3O4 nanoparticles were synthesized by solvethermal method. FeSO4ž7H2O and NaBH4 were respectively dissolved in distilled water, then moderated Fe3O4 particles and surfactant(PVP) were ultrasonic dispersed into the FeSO4ž7H2O solution. The resulting solution was stirred 2 h at room temperature. Fe could be deposited on the surface of monodispersed Fe3O4 nanoparticles to form core-shell particles. The particles were characterized by using various experimental techniques, such as transmission electron microscopy (TEM), X-ray diffraction (XRD), AGM and DTA. The results suggest that the saturation magnetization of the nanocomposites is 100 emu/g. The composition of the samples show monodisperse and the sides of the core/shell nanoparticles are 20-30nm. It is noted that the formation of Fe3O4/Fe nanocomposites magnetite nanoparticles possess superparamagnetic property.

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