scholarly journals Effect of Pretreatment on Magnetic Nanoparticle Growth on Graphene Surface and Magnetic Performance in Electroless Plating

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Kyunbae Lee ◽  
Taehoon Kim ◽  
Sang Bok Lee ◽  
Byung Mun Jung
Keyword(s):  
Magnetic Material ◽  
Magnetic Properties ◽  
Saturation Magnetization ◽  
Electroless Plating ◽  
Magnetic Nanoparticle ◽  
High Concentration ◽  
Graphene Surface ◽  
Future Studies ◽  
Nanoparticle Growth ◽  
Magnetic Performance

Electroless plating involves sensitization, activation, and plating processes. Sensitization and activation are conducted by dipping the substrate in SnCl2 solution and PdCl2 solution, respectively. These pretreatment processes are required to plate the substrate with noncatalytic surfaces. We investigated the effect of sensitization on the magnetic properties of FeCoNi@graphene hybrids prepared via electroless plating. The solution concentrations during sensitization were varied to observe changes in the structural, morphological, and magnetic properties of FeCoNi@graphene using XRD, TEM, and VSM, respectively. Sensitization under high concentration produced a large amount of SnO2, resulting in low saturation magnetization. Further, the FeCoNi@graphene hybrid prepared via electroless plating without sensitization also exhibited low saturation magnetization owing to the formation of oxides and hydroxides. We prepared FeCoNi@graphene with a saturation magnetization of 40.8 emu/g under sensitization at low concentration; this is the highest saturation magnetization among the reported magnetic material@graphene hybrids prepared via electroless plating. This study provides guidelines for the pretreatment of graphene via electroless plating and should contribute to future studies on the synthesis of magnetic material@graphene hybrids.

scholarly journals Electrical and Magnetic Properties of Polymer Electrolyte (PVA:LiOH) Containing In Situ Dispersed Fe3O4 Nanoparticles

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
M. P. Aji ◽  
Rahmawati ◽  
Masturi ◽  
S. Bijaksana ◽  
Khairurrijal ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Polymer Electrolyte ◽  
Polymer Electrolytes ◽  
Poly Vinyl Alcohol ◽  
High Concentration ◽  
Nanoparticle Growth ◽  
Electrical And Magnetic Properties ◽  
Maximum Conductivity ◽  
Host Polymer

Nanocomposite magnetic polymer electrolytes based on poly(vinyl alcohol) (PVA) complexed with lithium hydroxide (LiOH) and containing magnetite (Fe3O4) nanoparticles were prepared using an in situ method, in which the nanoparticles were grown in the host polymer electrolyte. Ion carriers were formed during nanoparticle growth from the previously added LiOH precursor. If a high concentration of LiOH was added, the remaining unreacted LiOH was distributed in the form of an amorphous complex around the Fe3O4 nanoparticles, thus preventing agglomeration of the nanoparticles by the host polymer. By addition of Fe3O4 the composite polymer electrolytes improved the ionic conductivity, resulting in a maximum conductivity of 1.81×10-3 S⋅cm-1. The magnetic properties of the polymer electrolyte were investigated through magnetic susceptibility studies, and the material was predominantly ferromagnetic.

scholarly journals Preparation and Magnetic Properties of Anisotropic (Sm,Pr)Co5/Fe Nanocomposites Particles via Electroless Plating

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Shi Wang ◽  
Jin-Ming Ma ◽  
Yan Chen
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Saturation Magnetization ◽  
Ball Milling ◽  
Electroless Plating ◽  
Coating Layer ◽  
Complexing Agent ◽  
Fe Content ◽  
20 Nm

Anisotropic (Sm,Pr)Co5/Fe nanocomposites particles were prepared by electroless plating iron on the surface of (Sm,Pr)Co5nanoflakes after being prepared by ball milling for 4 h. A uniform and continuous coating layer was obtained due to the addition of complexing agent and the particle size of the reduced Fe particles was in the range of 10~20 nm. When the nominal addition of Fe was 15 wt%, the nanocomposites show enhanced remnant and saturation magnetization:Mr=53.35 emu/g,Ms=73.08 emu/g compared to the noncoated nanoflakes withMr=48.52 emu/g,Ms=60.15 emu/g, while the coercivity drops from 10.33 kOe to 8.89 kOe. The effect of Fe content on the magnetic properties of the magnets is also discussed.

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.

The Structure and Magnetic Properties of NiZn-Ferrite Films Deposited by Magnetron Sputtering at Room Temperature

2013 ◽  
Vol 690-693 ◽  
pp. 1702-1706 ◽  
Author(s):  
Shuang Jun Nie ◽  
Hao Geng ◽  
Jun Bao Wang ◽  
Lai Sen Wang ◽  
Zhen Wei Wang ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Magnetron Sputtering ◽  
Saturation Magnetization ◽  
Room Temperature ◽  
Oxygen Flow ◽  
Flow Ratio ◽  
Study Results ◽  
Ferrite Thin Films ◽  
Ferrite Films

NiZn-ferrite thin films were deposited onto silicon and glass substrates by radio frequency magnetron sputtering at room temperature. The effects of the relative oxygen flow ratio on the structure and magnetic properties of the thin films were investigated. The study results reveal that the films deposited under higher relative oxygen flow ratio show a better crystallinity. Static magnetic measurement results indicated that the saturation magnetization of the films was greatly affected by the crystallinity, grain dimension, and cation distribution in the NiZn-ferrite films. The NiZn-ferrite thin films with a maximum saturation magnetization of 151 emucm-3, which is about 40% of the bulk NiZn ferrite, was obtained under relative oxygen flow ratio of 60%.

scholarly journals Specific Absorption Rate Dependency on the Co2+ Distribution and Magnetic Properties in CoxMn1-xFe2O4 Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1231
Author(s):  
Venkatesha Narayanaswamy ◽  
Imaddin A. Al-Omari ◽  
Aleksandr S. Kamzin ◽  
Bashar Issa ◽  
Huseyin O. Tekin ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Field Strength ◽  
Saturation Magnetization ◽  
Absorption Rate ◽  
Specific Absorption Rate ◽  
Ferrite Nanoparticles ◽  
Cofe2o4 Nanoparticles ◽  
Specific Absorption ◽  
Octahedral Sites ◽  
Mixed Ferrite

Mixed ferrite nanoparticles with compositions CoxMn1-xFe2O4 (x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0) were synthesized by a simple chemical co-precipitation method. The structure and morphology of the nanoparticles were obtained by X-ray diffraction (XRD), transmission electron microscope (TEM), Raman spectroscopy, and Mössbauer spectroscopy. The average crystallite sizes decreased with increasing x, starting with 34.9 ± 0.6 nm for MnFe2O4 (x = 0) and ending with 15.0 ± 0.3 nm for CoFe2O4 (x = 1.0). TEM images show an edge morphology with the majority of the particles having cubic geometry and wide size distributions. The mixed ferrite and CoFe2O4 nanoparticles have an inverse spinel structure indicated by the splitting of A1g peak at around 620 cm−1 in Raman spectra. The intensity ratios of the A1g(1) and A1g(2) peaks indicate significant redistribution of Co2+ and Fe3+ cations among tetrahedral and octahedral sites in the mixed ferrite nanoparticles. Magnetic hysterics loops show that all the particles possess significant remnant magnetization and coercivity at room temperature. The mass-normalized saturation magnetization is highest for the composition with x = 0.8 (67.63 emu/g), while CoFe2O4 has a value of 65.19 emu/g. The nanoparticles were PEG (poly ethylene glycol) coated and examined for the magneto thermic heating ability using alternating magnetic field. Heating profiles with frequencies of 333.45, 349.20, 390.15, 491.10, 634.45, and 765.95 kHz and 200, 250, 300, and 350 G field amplitudes were obtained. The composition with x = 0.2 (Co0.2Mn0.8Fe2O4) with saturation magnetization 57.41 emu/g shows the highest specific absorption rate (SAR) value of 190.61 W/g for 10 mg/mL water dispersions at a frequency of 765.95 kHz and 350 G field strength. The SAR values for the mixed ferrite and CoFe2O4 nanoparticles increase with increasing concentration of particle dispersions, whereas for MnFe2O4, nanoparticles decrease with increasing the concentration of particle dispersions. SARs obtained for Co0.2Mn0.8Fe2O4 and CoFe2O4 nanoparticles fixed in agar ferrogel dispersions at frequency of 765.95 kHz and 350 G field strength are 140.35 and 67.60 W/g, respectively. This study shows the importance of optimizing the occupancy of Co2+ among tetrahedral and octahedral sites of the spinel system, concentration of the magnetic nanoparticle dispersions, and viscosity of the surrounding medium on the magnetic properties and heating efficiencies.

The Influence of Composition on Morphology, Structure and Magnetic Properties of Ni-Co Films on Aluminum Prepared by Electroplating Method

2013 ◽  
Vol 303-306 ◽  
pp. 2505-2509
Author(s):  
Yong Jun Hu ◽  
Dong Cao ◽  
Xi Qiang Li ◽  
Hui Ting Zheng ◽  
Xiao Ling Cheng ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Saturation Magnetization ◽  
Crystal Orientation ◽  
Nickel Content ◽  
Cobalt Content ◽  
Preferential Orientation ◽  
Content Increase ◽  
Composition Change ◽  
Alloy Films ◽  
Similar Composition

In this paper, Ni-Co alloy films with different composition were obtained by means of electroplating method. The morphology, structure and magnetic properties of Ni-Co alloy films with different Cobalt content are evaluated. The effect of the crystal orientation on the morphology of Ni-Co deposits with different compositon was discussed. The results showed that Ni–Co alloy films with Cobalt content decrease is composed of pyramidal, spindly, mixed pyramidal and spindly, and cellular particles respectively. To the deposits with similar composition, change of morphology is related to the preferential orientation. With the increase of the Nickel content, the saturation magnetization (Ms) value of the Ni–Co alloy films increases and then decreases sharply. The coercivety (Hc) value of the Ni–Co alloy films decreases with the Nickel content increase.

Research on Effects of Mo Element on the Magnetic Properties of 1J79 Alloy

2010 ◽  
Vol 160-162 ◽  
pp. 1787-1790
Author(s):  
Jing Cao ◽  
Yong Feng Wang ◽  
Chun Xue Wei
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Crystal Growth ◽  
Saturation Magnetization ◽  
Electron Probe ◽  
Electric Arc ◽  
Experimental Results ◽  
Vibrating Sample Magnetometer ◽  
Electron Probe Microanalyzer ◽  
Mo Content

1J79 alloy was prepared by vacuum electric arc smelting．The crystal growth and the content of impurity was observed by electron probe microanalyzer，and magnetic properties were measured by vibrating sample magnetometer(VSM)．Experimental results show that inclusions in the alloy are fewer and fewer, composition becomes more uniform with the increases of the Mo content, and grain size also becomes larger and larger with the increases of Mo content, to reduce coercivity. The small amount of Mo addition is useful to improve the saturation magnetization and reduce coercivity．

scholarly journals Ferromagnetic Properties of N-Doped and Undoped TiO2 Rutile Single-Crystal Wafers with Addition of Tungsten Trioxide

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1934 ◽  
Author(s):  
Jing Xu ◽  
Haiying Wang ◽  
Zhongpo Zhou ◽  
Zhaorui Zou
Keyword(s):  
Magnetic Properties ◽  
Single Crystal ◽  
Saturation Magnetization ◽  
Photoelectron Spectroscopy ◽  
Oxygen Vacancies ◽  
Tio2 Surface ◽  
Doped Tio2 ◽  
X Ray ◽  
N Doping ◽  
Tio2 Rutile

In this work, undoped, N-doped, WO3-loaded undoped, and WO3-loaded with N-doped TiO2 rutile single-crystal wafers were fabricated by direct current (DC) magnetron sputtering. N-doping into TiO2 and WO3 loading onto TiO2 surface were used to increase and decrease oxygen vacancies. Various measurements were conducted to analyze the structural and magnetic properties of the samples. X-ray diffraction results showed that the N-doping and WO3 loading did not change the phase of all samples. X-ray photoelectron spectroscopy results revealed that W element loaded onto rutile single-crystal wafers existed in the form of WO3. UV-Vis spectrometer results showed that the absorption edge of WO3-loaded undoped and WO3-loaded with N-doped TiO2 rutile single-crystal wafers had red shift, resulting in a slight decrease in the corresponding band gap. Photoluminescence spectra indicated that oxygen vacancies existed in all samples due to the postannealing atmosphere, and oxygen vacancies density increased with N-doping, while decreasing with WO3 loading onto TiO2 surface. The magnetic properties of the samples were investigated, and the saturation magnetization values were in the order N-doped > WO3-loaded with N-doped > undoped > WO3-loaded undoped rutile single-crystal wafers, which was the same order as the oxygen vacancy densities of these samples. N-doping improved the saturation magnetization values, while WO3-loaded decreased the saturation magnetization values. This paper reveals that the magnetic properties of WO3-loaded with N-doped rutile single-crystal wafers originate from oxygen vacancies.

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