In-situ synthesis and magnetic properties of polystyrene/polypyrrole nanocomposite materials with uniformly dispersed iron nanoparticles

2003 ◽  
Vol 788 ◽  
Author(s):  
H. Srikanth ◽  
P. Poddar ◽  
J. L. Wilson ◽  
K. Mohomed ◽  
J. P. Harmon
Keyword(s):  
Magnetic Properties ◽  
Iron Nanoparticles ◽  
Magnetic Hysteresis ◽  
Surface Oxidation ◽  
Magnetic Hysteresis Loop ◽  
Processing Conditions ◽  
Uniform Dispersion ◽  
Good Uniform ◽  
Device Applications

ABSTRACTMagnetic nanoparticles embedded in polymer matrices have excellent potential for electromagnetic device applications like EMI noise reduction. We have synthesized polystyrene (PS) and polypyrrole (PPy) composites by controllably dispersing bare and PS-coated Fe nanoparticles. These nanocomposites were processed as spin-coated thin films as well as in bulk form. The processing conditions were optimized to achieve good uniform dispersion of the nanoparticles in the polymer matrix. SEM scans revealed clustering of nanoparticles which was particularly evident at the surface in the conducting polymer nanocomposites. Magnetic hysteresis loop measurements indicate large coercivities associated with the clusters and surface oxidation of the Fe particles. Overall, the excellent dispersion coupled with reasonable control over magnetic properties achieved in our experiments is promising for electromagnetic applications of these materials.

scholarly journals Developing a reference material set for the magnetic properties of NdFeB alloy-based hard magnetic materials

2019 ◽  
Vol 15 (1) ◽  
pp. 21-27
Author(s):  
E. A. Volegova ◽  
T. I. Maslova ◽  
V. O. Vas’kovskiy ◽  
A. S. Volegov
Keyword(s):  
Magnetic Properties ◽  
Magnetic Materials ◽  
Permanent Magnets ◽  
Magnetic Loss ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Magnetic Hysteresis Loop ◽  
Magnetic Characteristics ◽  
Hard Magnetic Materials ◽  
Certified Values

Introduction The introduction indicates the need for the use of permanent magnets in various technology fields. The necessity of measuring the limit magnetic hysteresis loop for the correct calculation of magnetic system parameters is considered. The main sources of error when measuring boundary hysteresis loops are given. The practical impossibility of verifying blocks of magnetic measuring systems element-by-element is noted. This paper is devoted to the development of reference materials (RMs) for the magnetic properties of hard magnetic materials based on Nd2Fe14B, a highly anisotropic intermetallic compound.Materials and measuring methods Nd-Fe-B permanent magnets were selected as the material for developing the RMs. RM certified values were established using a CYCLE‑3 apparatus included in the GET 198‑2017 State Primary Measurement Standard for units of magnetic loss power, magnetic induction of constant magnetic field in a range from 0.1 to 2.5 T and magnetic flux in a range from 1·10–5 to 3·10–2 Wb.Results and its discussion Based on the experimentally obtained boundary hysteresis loops, the magnetic characteristics were evaluated, the interval of permitted certified values was set, the measurement result uncertainty of certified values was estimated, the RM validity period was established and the first RM batch was released.Conclusion On the basis of conducted studies, the RM type for magnetic properties of NdFeB alloy-based hard magnetic materials was approved (MS NdFeB set). The developed RM set was registered under the numbers GSO 11059–2018 / GSO 11062–2018 in the State RM Register of the Russian Federation.

Structural and Magnetic Properties of Nano Composite (Ni1-xSrx Fe12 O19) Prepared by Sol-gel

2021 ◽  
Vol 19 (10) ◽  
pp. 20-28
Author(s):  
Dhifaf Hussain Hassan ◽  
Sabah Jalal Fathi
Keyword(s):  
Magnetic Properties ◽  
Hysteresis Loop ◽  
Quaternary Structure ◽  
Sol Gel ◽  
Magnetic Hysteresis ◽  
Magnetic Hysteresis Loop ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Two Phases ◽  
Hematite Fe2o3

The compound was prepared by sol-gel method for spontaneous combustion with certain weight ratios (x=0.0,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9), the samples were calcined at a temperature (900oC) for a period of two hours(2h), then studied its structural and magnetic properties.one of the most prominent results that we obtained from the X-ray diffraction technique (XRD) is that compound has several phases. Where the sample (NiFe2O4) appeared to be polycrystalline and the dominant phase in it is the cubic phase, while the other phase is (Hematite)(Fe2O3) A crystal structure rhomboid (Rhombohedral), in addition to these two phases, the phase with the existing quaternary structure appeared (Sr2Fe2O5) its called (Orthorhombic). The results of the magnetic properties that were obtained through the (VSM) device, and one of the most important of these properties is the magnetic hysteresis loop by analyzing the magnetic hysteresis loop at (x=0.3), where the least area of the hysteresis loop or the least width of the hysteresis loop One of the most important parameters of the magnetic properties is the saturation magnetism (μS) and its value ranges from (19.76-3.86) (emu/gr), the highest value was at (X=0.3) and its value is (19.76emu/gr) and in general its value decreases with increasing concentration of strontium. The residual magnetism (Mr) ranges between (7.45-1.58) (emu/gr), where it reached its highest value at (x=0.3) and its value is (7.45emu/gr), and generally its value decreases with increasing concentration of strontium. In addition to that, there is another parameter which is coercion or Magnetic coercivity (Hc) ranges in value (1751.104-209.26) (Oe), reaching its lowest value at (x=0.3), and then increases with increasing strontium concentration until it reaches its highest value at (x=0.9), where it reached its value is (1751.104Oe). The square rate represented by the symbol (μi) has high values. This means that there is a mutual coupling between the soft and hard magnetic phases, which was the highest value at (x=0.3) and its value is (4.93).

scholarly journals Core-Shell Nanostructure ofα-Fe2O3/Fe3O4: Synthesis and Photocatalysis for Methyl Orange

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Yang Tian ◽  
Di Wu ◽  
Xiao Jia ◽  
Binbin Yu ◽  
Sihui Zhan
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Methyl Orange ◽  
Molten Salts ◽  
Surface Oxidation ◽  
The Self ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles

Fe3O4nanoparticle was synthesized in the solution involving water and ethanol. Then,α-Fe2O3shell was produced in situ on the surface of theFe3O4nanoparticle by surface oxidation in molten salts, formingα-Fe2O3/Fe3O4core-shell nanostructure. It was showed that the magnetic properties transformed from ferromagnetism to superparamagnetism after the primaryFe3O4nanoparticles were oxidized. Furthermore, the obtainedα-Fe2O3/Fe3O4core-shell nanoparticles were used to photocatalyse solution of methyl orange, and the results revealed thatα-Fe2O3/Fe3O4nanoparticles were more efficient than the self-preparedα-Fe2O3nanoparticles. At the same time, the photocatalyzer was recyclable by applying an appropriate magnetic field.

Influence of Zinc-Zirconium Substitution on Magnetic Properties of Ba(ZnZr)xFe12-2xO19 Hexaferrite Prepared by the Molten Salt Method

2009 ◽  
Vol 79-82 ◽  
pp. 2071-2074 ◽  
Author(s):  
Hai Feng Li ◽  
Rong Zhou Gong ◽  
Xian Wang ◽  
Li Ren Fan ◽  
Gang He ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Molten Salt ◽  
Magnetic Hysteresis ◽  
Magnetic Hysteresis Loop ◽  
Chemical Compositions ◽  
Molten Salt Method ◽  
Vibrating Sample Magnetometer ◽  
Hexagonal Ferrites ◽  
X Ray Diffraction ◽  
X Ray

M-type hexaferrites Ba(ZnZr)xFe12-2xO19 (x=0, 0.5, 1.0, 1.5) powders, have been synthesized by molten salt method, where x varies from 0 to 1.5 in steps of 0.5. X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and vibrating sample magnetometer(VSM) were used to analyze the structures and magnetic properties. The results showed that, the magnetoplumbite structures for all samples calcining at 1100°C have been formed. The magnetic hysteresis loop measurements of the hexagonal ferrites powders showed that the saturation magnetization (Ms), the remanent magnetization (Mr), and the coercitivity (Hc) of ferrites depend strongly on the chemical compositions of materials. The data showed that the max Hc was obtained when substitution of x=1.0 (Hc=63.9 Oe), while the best Ms was obtained when substitution of x=0.5 (Ms=54.02 emu/g). Zn and Zr substitutions greatly modified the magnetic properties of BaM hexaferrite.

Tuning of magnetic properties of the 2D CN-bridged NiII–NbIV framework by incorporation of guest cations of alkali and alkaline earth metals

2021 ◽  
Author(s):  
Michał Heczko ◽  
Mateusz Reczyński ◽  
Christian Näther ◽  
Beata Nowicka
Keyword(s):  
Magnetic Properties ◽  
Hysteresis Loop ◽  
Coercive Field ◽  
Alkaline Earth ◽  
Magnetic Hysteresis ◽  
Magnetic Hysteresis Loop ◽  
Alkaline Earth Metals

The coercive field of the magnetic hysteresis loop of the 2D microporous honeycomb-like Ni–Nb network decreases with the increasing number and size of the s-block metal guest cations.

scholarly journals Si Interlayer Thickness Dependence of Hysteresis Loop in Co/Si/Co/GaAs(001)

2012 ◽  
Vol 4 (3) ◽  
pp. 561-567 ◽  
Author(s):  
J. Islam ◽  
Y. Yamamoto ◽  
E. Shikoh ◽  
A. Fujiwara ◽  
H. Hori
Keyword(s):  
Magnetic Properties ◽  
Hysteresis Loop ◽  
Buffer Layer ◽  
Coercive Field ◽  
Single Phase ◽  
Magnetic Hysteresis ◽  
Magnetic Hysteresis Loop ◽  
Interlayer Thickness ◽  
Two Phase ◽  
Cobalt Silicides

Magnetic hysteresis loop changes from two-phase to single-phase with decreasing Si interlayer thickness in Co/Si/Co/GaAs. Coercive field of 50 nm Co deposited on Si layer decreases with the increase of Si interlayer thickness. Deposition of Au layer between Co and Si changes the magnetic hysteresis loop. We propose that the formation of cobalt silicides at the interface of Co and Si modulate magnetic properties of the trilayer without Au buffer layer.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i3.10852 J. Sci. Res. 4 (3), 561-567 (2012)

On the Mechanical Properties Determination of Armco Steel Using Magnetic Hysteresis Loop and Barkhausen Noise

2011 ◽  
Vol 495 ◽  
pp. 269-271
Author(s):  
K. Kosmas
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Magnetic Properties ◽  
Hysteresis Loop ◽  
Mechanical Load ◽  
Magnetic Hysteresis ◽  
Magnetic Hysteresis Loop ◽  
Barkhausen Noise

Magnetic properties, namely B-H loops and Barkhausen noise, have been determined with respect to mechanical load in Armco steels. The monotonic response illustrated a clearly verified knee, corresponding to the initiation of plastic deformation.

scholarly journals Asymmetric Interfacial Intermixing Associated Magnetic Coupling in LaMnO3/LaFeO3 Heterostructures

2021 ◽  
Vol 9 ◽  
Author(s):  
Binbin Chen ◽  
Nicolas Gauquelin ◽  
Robert J. Green ◽  
Johan Verbeeck ◽  
Guus Rijnders ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Hysteresis Loop ◽  
Magnetic Hysteresis ◽  
Magnetic Coupling ◽  
Plain Film ◽  
Magnetic Hysteresis Loop ◽  
Scanning Transmission ◽  
Unit Cells ◽  
Chemical Profiles ◽  
Abrupt Interface

The structural and magnetic properties of LaMnO3/LaFeO3 (LMO/LFO) heterostructures are characterized using a combination of scanning transmission electron microscopy, electron energy-loss spectroscopy, bulk magnetometry, and resonant x-ray reflectivity. Unlike the relatively abrupt interface when LMO is deposited on top of LFO, the interface with reversed growth order shows significant cation intermixing of Mn3+ and Fe3+, spreading ∼8 unit cells across the interface. The asymmetric interfacial chemical profiles result in distinct magnetic properties. The bilayer with abrupt interface shows a single magnetic hysteresis loop with strongly enhanced coercivity, as compared to the LMO plain film. However, the bilayer with intermixed interface shows a step-like hysteresis loop, associated with the separate switching of the “clean” and intermixed LMO sublayers. Our study illustrates the key role of interfacial chemical profile in determining the functional properties of oxide heterostructures.

Correlation of micro-structural, micro-chemical and micro-magnetic properties of longitudinal recording media using CM20FEG Lorentz TEM

1994 ◽  
Vol 52 ◽  
pp. 892-893
Author(s):  
T. P. Nolan ◽  
R. Sinclair ◽  
T. Yamashita ◽  
R. Ranjan
Keyword(s):  
Magnetic Properties ◽  
Magnetic Recording ◽  
Magnetic Hysteresis ◽  
Hard Disk Drives ◽  
Magnetic Hysteresis Loop ◽  
Low Noise ◽  
Atomic Scale ◽  
Second Phase ◽  
Recording Media ◽  
Tem Analysis

Cobalt alloy on chromium thin film magnetic media are used in industry computer hard disk drives because of their large values of coercivity (Hc), remanent magnetization (Mr), squareness (S*), and relatively low noise. The magnetic performance depends strongly on processing conditions and the resulting nanometer scale microstructure.A complete structure-processing-properties analysis requires effective measurement of magnetic and microstructural properties. To date, most structure-properties analyses have involved correlation of bulk magnetic (hysteresis loop) properties and magnetic recording measurements with physical microstructures observed by high-resolution SEM and TEM.The nanoscale microstructural features that dramatically affect magnetic properties are difficult to observe but careful TEM analysis has been used to observe subtle, important differences in the atomic scale physical microstructure. Even these impressive capabilities are becoming insufficient for continued development of improved magnetic recording media. Microstructural design is moving into a regime where appropriate control of magnetic properties requires control of elemental composition and second phase formation as well as crystallography and morphology, at near-atomic levels.

Structural, Thermal, Morphological and Magnetic Properties of Al3+-Doped Nanostructured Spinel Nickel Ferrites

2021 ◽  
Vol 13 (5) ◽  
pp. 794-802
Author(s):  
Sami-ullah Rather ◽  
Abdulrahim Ahmad Al-Zahrani ◽  
Usman Saeed ◽  
O. M. Lemine ◽  
Saad S. A. Al-Shahrani ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Nickel Ferrite ◽  
Crystal Size ◽  
Magnetic Hysteresis ◽  
Exchange Interactions ◽  
Magnetic Hysteresis Loop ◽  
Nominal Composition ◽  
Average Crystal Size ◽  
Scanning Calorimetry ◽  
X Ray

Aluminum–nickel ferrite nanostructure with a nominal composition of NiFe2-xAlxO4 (0 < x < 0.9) was synthesized by heat treatment process by employing polyvinylpyrrolidone (PVP) as a capping operator. The effects of Al3+ substitution on structural, morphological, quantitative, qualitative and magnetic properties were characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron microscopy (XPS) and vibrating-sample magnetometry (VSM). Single-phase inverse spinel structure and decrease in average crystal size as Al concentration increases was acknowledged by XRD and EDX characterization. The decrease in average crystal size as Al3+ ions content increases is associated with structural effects of overall crystal size of nanostructure. The development of a thermally stable nickel ferrite above 500 °C was detected by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) measurements. The magnetic hysteresis loop measurements at room temperature (RT) with an ultimate tested magnetic field of 1.8 T shows both saturation and remnant magnetization decreases as content of Al3+ ions substitution increases. The decrease in overall magnetization is due to spin non-collinearity, weakening of magnetocrystalline anisotropy and weak super-exchange interactions.

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