Magnetic Properties of γ-Fe2O3/Poly(Ether-Ester) Nanocomposites

2008 ◽  
Vol 8 (4) ◽  
pp. 2127-2134 ◽  
Author(s):  
N. Guskos ◽  
V. Likodimos ◽  
S. Glenis ◽  
M. Maryniak ◽  
M. Baran ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Nanoparticles ◽  
Magnetic Behavior ◽  
Thermoplastic Elastomer ◽  
Relaxation Processes ◽  
Close Correspondence ◽  
Polycondensation Reaction ◽  
Dispersion State ◽  
Ether Ester

The magnetic properties of γ-Fe2O3 nanoparticles embedded in a thermoplastic elastomer poly(ether-ester) copolymer by the in situ polycondensation reaction process have been investigated by means of magnetization and ferromagnetic resonance (FMR) measurements at low filler concentrations of 0.1 and 0.3 wt% with the magnetic additive introduced in the polymer matrix in powder and solution form. The magnetic behavior of the magnetopolymeric nanocomposites indicates significant interparticle interaction effects that depend mainly on the dispersion state of the magnetic nanoparticles as well as their concentration, consistent with the variation of the particle microstructure characterized by magnetic aggregates in the nanometer and micron scale for the solution and powder dispersions, respectively. The magnetization and FMR results at different filler concentrations and dispersions showa close correspondence to the relaxation processes of the copolymer, implying the coupling of polymeric and magnetic properties.

In situ synthesis, morphology and magnetic properties of poly(ether–ester) multiblock copolymer/carbon-covered nickel nanosystems

2010 ◽  
Vol 356 (37-40) ◽  
pp. 1893-1901 ◽  
Author(s):  
N. Guskos ◽  
J. Typek ◽  
B.V. Padlyak ◽  
Yu K. Gorelenko ◽  
I. Pelech ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
In Situ Synthesis ◽  
Multiblock Copolymer ◽  
Ether Ester

scholarly journals Tunable magnetism on the lateral mesoscale by post-processing of Co/Pt heterostructures

2015 ◽  
Vol 6 ◽  
pp. 1082-1090 ◽  
Author(s):  
Oleksandr V Dobrovolskiy ◽  
Maksym Kompaniiets ◽  
Roland Sachser ◽  
Fabrizio Porrati ◽  
Christian Gspan ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Behavior ◽  
Basic Research ◽  
Post Processing ◽  
Transmission Electron ◽  
Spin Dependent Transport ◽  
Complementary Approach ◽  
Dependent Transport ◽  
High Degree

Controlling magnetic properties on the nanometer-scale is essential for basic research in micro-magnetism and spin-dependent transport, as well as for various applications such as magnetic recording, imaging and sensing. This has been accomplished to a very high degree by means of layered heterostructures in the vertical dimension. Here we present a complementary approach that allows for a controlled tuning of the magnetic properties of Co/Pt heterostructures on the lateral mesoscale. By means of in situ post-processing of Pt- and Co-based nano-stripes prepared by focused electron beam induced deposition (FEBID) we are able to locally tune their coercive field and remanent magnetization. Whereas single Co-FEBID nano-stripes show no hysteresis, we find hard-magnetic behavior for post-processed Co/Pt nano-stripes with coercive fields up to 850 Oe. We attribute the observed effects to the locally controlled formation of the CoPt L10 phase, whose presence has been revealed by transmission electron microscopy.

Temperature Dependence of the FMR Spectra of Polymer Composites with Nanocrystalline α-Fe/C Filler

2007 ◽  
Vol 128 ◽  
pp. 213-218 ◽  
Author(s):  
N. Guskos ◽  
M. Maryniak ◽  
J. Typek ◽  
Iwona Pełech ◽  
Urszula Narkiewicz ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Temperature Dependence ◽  
Nanocrystalline Material ◽  
Magnetic Interactions ◽  
Benzene Rings ◽  
The Matrix ◽  
Nanocrystalline Iron ◽  
The Right ◽  
Ether Ester

Two different concentrations of nanocrystalline material: α-Fe/C were prepared by the carburization of nanocrystalline iron and characterized by XRD and SEM. The nanoparticles were next used as fillers in polymer nanocomposites using the in situ polycondensation reaction in a poly(ether-ester) matrix with two concentrations: 0.1 wt. % and 0.3 wt. %. The temperature dependence of the ferromagnetic resonance (FMR) spectra was investigated to study magnetic interactions in the compounds. The introduced FMR parameters (intensity and position of the right peak) describe well the temperature dependence of FMR spectra of strongly interacting magnetic nanoparticles. The FMR spectra depend strongly on the concentration of magnetic nanoparticles, which influence the magnetic interactions between them. Two main critical points of the matrix (the glass state and the freezing of benzene rings) influence the behaviour of the FMR spectra.

scholarly journals Microstructure and Magnetic Properties of Highly Ordered SBA-15 Nanocomposites Modified withFe2O3andCo3O4Nanoparticles

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
P. F. Wang ◽  
H. X. Jin ◽  
M. Chen ◽  
D. F. Jin ◽  
B. Hong ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Nanoparticles ◽  
Exchange Coupling ◽  
Sol Gel ◽  
Coupling Interaction ◽  
A Value ◽  
Hydrothermal Processes ◽  
Exchange Coupling Interaction ◽  
Microstructure And Magnetic Properties

Owing to the unique order mesopores, mesoporous SBA-15 could be used as the carrier of the magnetic nanoparticles. The magnetic nanoparticles in the frame and the mesopores lead to the exchange-coupling interaction or other interactions, which could improve the magnetic properties of SBA-15 nanocomposites. Mesoporous Fe/SBA-15 had been prepared via in situ anchoring Fe2O3into the frame and the micropores of SBA-15 using the sol-gel and hydrothermal processes. Co3O4nanoparticles had been impregnated into the mesopores of Fe/SBA-15 to form mesoporous Fe/SBA-15-Co3O4nanocomposites. XRD, HRTEM, VSM, and N2physisorption isotherms were used to characterize the mesostructure and magnetic properties of the SBA-15 nanocomposites, and all results indicated that the Fe2O3nanoparticles presented into the frame and micropores, while the Co3O4nanoparticles existed inside the mesopores of Fe/SBA-15. Furthermore, the magnetic properties of SBA-15 could be conveniently adjusted by the Fe2O3and Co3O4magnetic nanoparticles. Fe/SBA-15 exhibited ferromagnetic properties, while the impregnation of Co3O4nanoparticles greatly improved the coercivity with a value of 1424.6 Oe, which was much higher than that of Fe/SBA-15.

Magnetic Properties of a New One-Dimensional Vanadium Oxide with the Hollandite Structure.

2004 ◽  
Vol 848 ◽  
Author(s):  
Natasha A. Chernova ◽  
J. Katana Ngala ◽  
Peter Y. Zavalij ◽  
M. Stanley Whittingham
Keyword(s):  
Magnetic Properties ◽  
Transition Temperature ◽  
Vanadium Oxide ◽  
Ac Susceptibility ◽  
Relaxation Times ◽  
Magnetic Behavior ◽  
Relaxation Processes ◽  
Zero Field ◽  
Weiss Temperature ◽  
Temperature Dependences

ABSTRACTThe magnetic properties of the first hollandite-type vanadium oxide containing anions in the 2×2 channels, V7.22O8(OH)8(Cl)0.77(H3O)2.34, are studied using static (DC) and dynamic (AC) magnetic susceptibilities. From the high-temperature Curie-Weiss behavior the effective magnetic moment is found consistent with the 3+ vanadium oxidation state; the negative Curie-Weiss temperature Θ ≈ -500 K indicates strong antiferromagnetic exchange. The DC magnetic susceptibility shows a rapid increase and the AC susceptibility shows a maximum at about 20 K, indicating magnetic phase transition. The field-cooled and zero-field-cooled susceptibilities diverge below the transition temperature. The real and imaginary components of the AC susceptibility show frequency dependence and shift of maximum toward lower temperatures with decreasing frequency. Analysis of the frequency dependences reveals at least three different relaxation processes existing around and below the transition temperature. The temperature dependences of their relaxation times were obtained using Cole-Cole analysis. We show that the magnetic behavior observed is well explained by the random-field Ising model, with randomness brought on by vacancies in vanadium sites.

scholarly journals Magnetic Properties Study of Iron Oxide Nanoparticles-Loaded Poly(ε-caprolactone) Nanofibres

2021 ◽  
Vol 7 (5) ◽  
pp. 61
Author(s):  
Wojciech Sas ◽  
Małgorzata Jasiurkowska-Delaporte ◽  
Paweł Czaja ◽  
Piotr Maciej Zieliński ◽  
Magdalena Fitta
Keyword(s):  
Magnetic Properties ◽  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Detailed Analysis ◽  
Iron Oxide Nanoparticles ◽  
Physicochemical Characterization ◽  
Magnetic Behavior ◽  
Oxide Nanoparticles ◽  
Electrospun Nanofibres ◽  
Dynamic Magnetic Susceptibility

Magnetic nanofibres have attracted more and more attention recently due to their possible applications e.g., in spintronics and neuromorphic computing. This work presents the synthesis and physicochemical characterization of the electrospun nanofibres of poly(ε-caprolactone) (PCL) doped by iron oxide nanoparticles with diameters of 5 nm. PCL is a semi-crystalline, hydrophilic polymer showing controllable biodegradation rates, biocompatibility, and flexible mechanical properties. In the composite material, two different concentrations of magnetic nanoparticles were used: 2 and 6 wt.%. PCL-based composites were investigated using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetry (TGA). Although in the literature one can find many studies on magnetic polymeric composites, the investigation of their magnetic properties is usually limited to measuring the magnetization curve. Detailed analysis of dynamic magnetic susceptibility is rather rare. In this report, special attention was paid to the detailed analysis of magnetic properties, where we followed the evolution of changes in the magnetic behavior of the material depending on the concentration of magnetic nanoparticles.

Magnetic Properties of xCeO2•(50 − x) PbO•50B2O3 Glasses and Glass Ceramics

2017 ◽  
Vol 13 (1) ◽  
pp. 4486-4494 ◽  
Author(s):  
G.El Damrawi ◽  
F. Gharghar
Keyword(s):  
Magnetic Properties ◽  
Large Scale ◽  
Glass Ceramics ◽  
Magnetic Behavior ◽  
Crystal Formation ◽  
Dual Roles ◽  
Effective Agent ◽  
Ordered Structures ◽  
Essential Change

Cerium oxide in borate glasses of composition xCeO2·(50 − x)PbO·50B2O3 plays an important role in changing both microstructure and magnetic behaviors of the system. The structural role of CeO2 as an effective agent for cluster and crystal formation in borate network is clearly evidenced by XRD technique. Both structure and size of well-formed cerium separated clusters have an effective influence on the structural properties. The cluster aggregations are documented to be found in different range ordered structures, intermediate and long range orders are the most structures in which cerium phases are involved. The nano-sized crystallized cerium species in lead borate phase are evidenced to have magnetic behavior.  The criteria of building new specific borate phase enriched with cerium as ferrimagnetism has been found to keep the magnetization in large scale even at extremely high temperature. Treating the glass thermally or exposing it to an effective dose of ionized radiation is evidenced to have an essential change in magnetic properties. Thermal heat treatment for some of investigated materials is observed to play dual roles in the glass matrix. It can not only enhance alignment processes of the magnetic moment but also increases the capacity of the crystallite species in the magnetic phases. On the other hand, reverse processes are remarked under the effect of irradiation. The magnetization was found to be lowered, since several types of the trap centers which are regarded as defective states can be produced by effect of ionized radiation. 

Structural, Morphological and Magnetic Characterization of Sm-substituted Ni-Zn Ferrite

2020 ◽  
Vol 10 (2) ◽  
pp. 152-156 ◽  
Author(s):  
Muhammad Hanif bin Zahari ◽  
Beh Hoe Guan ◽  
Lee Kean Chuan ◽  
Afiq Azri bin Zainudin
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
Saturation Magnetization ◽  
Sol Gel ◽  
Magnetic Behavior ◽  
Rare Earth Ions ◽  
Ion Concentration ◽  
Zn Ferrite ◽  
Auto Combustion ◽  
Combustion Technique

Background: Rare earth materials are known for its salient electrical insulation properties with high values of electrical resistivity. It is expected that the substitution of rare earth ions into spinel ferrites could significantly alter its magnetic properties. In this work, the effect of the addition of Samarium ions on the structural, morphological and magnetic properties of Ni0.5Zn0.5SmxFe2-xO4 (x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) synthesized using sol-gel auto combustion technique was investigated. Methods: A series of Samarium-substituted Ni-Zn ferrite nanoparticles (Ni0.5Zn0.5SmxFe2-xO4 where x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by sol-gel auto-combustion technique. Structural, morphological and magnetic properties of the samples were examined through X-Ray Diffraction (XRD), Field-Emission Scanning Electron Microscope (FESEM) and Vibrating Sample Magnetometer (VSM) measurements. Results: XRD patterns revealed single-phased samples with spinel cubic structure up to x= 0.04. The average crystallite size of the samples varied in the range of 41.8 – 85.6 nm. The prepared samples exhibited agglomerated particles with larger grain size observed in Sm-substituted Ni-Zn ferrite as compared to the unsubstituted sample. The prepared samples exhibited typical soft magnetic behavior as evidenced by the small coercivity field. The magnetic saturation, Ms values decreased as the Sm3+ concentration increases. Conclusion: The substituted Ni-Zn ferrites form agglomerated particles inching towards more uniform microstructure with each increase in Sm3+ substitution. The saturation magnetization of substituted samples decreases with the increase of samarium ion concentration. The decrease in saturation magnetization can be explained based on weak super exchange interaction between A and B sites. The difference in magnetic properties between the samples despite the slight difference in Sm3+ concentrations suggests that the properties of the NiZnFe2O4 can be ‘tuned’, depending on the present need, through the substitution of Fe3+ with rare earth ions.

In situ deposition of magnetic nanoparticles on glass mat using plasma sputtering method

2021 ◽  
pp. 1-11
Author(s):  
Sheila Shahidi ◽  
Sanaz Dalalsharifi ◽  
Mahmood Ghoranneviss ◽  
Rattanaphol Mongkholrattanasit
Keyword(s):  
Magnetic Nanoparticles ◽  
Plasma Sputtering ◽  
In Situ Deposition ◽  
Glass Mat
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