SiO2-Coated Fe-Ni Alloy Core–Shell Structures Synthesized by a Facile Chemical Method

2016 ◽  
Vol 697 ◽  
pp. 303-306
Author(s):  
Guo Jun Li ◽  
Yun Hui Mei ◽  
Feng Hou
Keyword(s):  
Magnetic Properties ◽  
Spherical Particles ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Soft Magnetic ◽  
Alloy Particles ◽  
Transmission Electron ◽  
Ni Alloy ◽  
Wet Chemical ◽  
Silica Layers

Fe-Ni@ SiO2core–shell structured micrometer spherical particles with nanometer thick SiO2 shell were fabricated by a facile wet chemical process, their compositions and mechanisms were investigated using x-ray diffraction and Fourier transform of infra-red spectra, and their microstructures and magnetic properties were analyzed by high-resolution transmission electron microscopy and vibrating sample magnetometer. The structure of the synthesized SiO2-coated Fe-Ni alloy particles varied with adding TEOS contents. As-prepared Fe-Ni@SiO2 composites exhibit typical soft magnetic properties. Their highest saturation magnetization approximately linear decreases from 176 emu g−1for pure Fe-Ni alloy powders to 121 emu g−1for the coated powders with 20nm amorphous silica layers, but the coercivity of all different thickness SiO2-coated Fe-Ni alloy powders maintains in the range of about 25 Oe.

Influence of Alloying Additions on Enhancement of Soft Magnetic Properties Effect and Crystallization in FeXSiB (X=Cu, V, Co, Zr, Nb) Amorphous Alloys

2007 ◽  
Vol 130 ◽  
pp. 171-174 ◽  
Author(s):  
Z. Stokłosa ◽  
G. Badura ◽  
P. Kwapuliński ◽  
Józef Rasek ◽  
G. Haneczok ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Crystallization Process ◽  
Annealing Temperature ◽  
Magnetic Measurements ◽  
X Ray Diffraction ◽  
Soft Magnetic ◽  
X Ray ◽  
Second Stage ◽  
Transmission Electron

The crystallization and optimization of magnetic properties effects in FeXSiB (X=Cu, V, Co, Zr, Nb) amorphous alloys were studied by applying X-ray diffraction methods, high resolution transmission electron microscopy (HRTEM), resistometric and magnetic measurements. The temperatures of the first and the second stage of crystallization, the 1h optimization annealing temperature and the Curie temperature were determined for different amorphous alloys. Activation energies of crystallization process were obtained by applying the Kissinger method. The influence of alloy additions on optimization effect and crystallization processes was carefully examined.

scholarly journals A Novel Fabrication of Spherical Fe50ni50 Alloy Powders via in-Situ De-Wetting of Liquid Solid Interface

Crystals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 325
Author(s):  
Song ◽  
Lei ◽  
Zhong
Keyword(s):  
Spherical Shape ◽  
Soft Magnetic Property ◽  
Spherical Particles ◽  
Soft Magnetic ◽  
Sem Images ◽  
Cross Sectional ◽  
Alloy Particles ◽  
Ni Alloy ◽  
Alumina Particles

: Spherical Fe50Ni50 alloy powders were fabricated via a novel route based on in-situ interface de-wetting between liquid Fe-Ni alloy and alumina. The obtained Fe50Ni50 alloy particles exhibit very good spherical shape according to SEM images. Furthermore, the cross-sectional SEM images show that there are no pores and bulk inclusions in the internal region of the spherical particles. The XRD results show a trace amount of the impurity alumina phase appearing in taenite phase. The size distribution agreed well with the SEM observation confirms that the alumina powders successfully segregated pre-alloy powders. As an incidental benefit, the surface alumina particles were treated as the electrical insulation coatings. The magnetic character shows that spherical Fe50Ni50 powders exhibit a good soft magnetic property even though with a slightly decreasing of saturation magnetization due to non-magnetic coatings. Our strategies provide a method to in-situ fabricate insulation coated Fe-Ni spherical alloy powders as magnetic powder core.

Nanocrystallization of Fe-Based Amorphous Alloys Fe73.5Cu1Nb3Si13.5B9 by Yb-Doped Fiber Laser Overlapping Irradiation

2012 ◽  
Vol 482-484 ◽  
pp. 2365-2370 ◽  
Author(s):  
Qian Li Ma ◽  
Yong Bao ◽  
Guo Rui Zhang ◽  
Li Meng Yu ◽  
Ling Fei Ji ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Fiber Laser ◽  
Laser Irradiation ◽  
Soft Magnetic Property ◽  
Internal Diameter ◽  
Soft Magnetic Properties ◽  
External Diameter ◽  
X Ray Diffraction ◽  
Soft Magnetic ◽  
Transmission Electron

The paper presents a laser irradiation method for rapidly fabricating Fe-based nanocrystalline alloys using Yb-doped fiber laser with a wavelength of 1070nm by overlapping irradiation of the heated areas. The samples are annular cores rolled with 20μm-thick and 3.2mm-wide belts of amorphous alloy Fe73.5Cu1Nb3Si13.5B9, which have internal diameter of 14 mm and external diameter of 20 mm. Every side of the samples is irradiated for 15 min by fiber laser. X-ray diffraction and transmission electron microscopy (TEM) are used for microstructure analysis and observation. The samples irradiated by a defocus beam with a diameter of 7.1mm through a lens have better soft magnetic properties than directly by an original collimating beam with a diameter of 6.7mm. The dimension of homogeneous ultrafine grains is about 10nm with a bcc α-Fe (Si), which is the foundation of the excellent soft magnetic property. Uniform laser irradiation and the appropriate laser power are necessary for optimum microstructure and soft magnetic properties.

scholarly journals Conductivity Research on ABS & PC Converted Core Shell Quantum Dot Doped in ABS & PC

2019 ◽  
Vol 8 (4) ◽  
pp. 7740-7742
Keyword(s):  
Quantum Dot ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Wet Chemical ◽  
Uv Visible ◽  
Lcr Meter ◽  
Absorption Characteristics

Zns: Mn / ZnO inverted shell quantum dots have been synthesized using a wet chemical process.The study used Mn of 4 percent weight. Transmission Electron Microscope (TEM) images show a 50 nm order for the quantum dot size. Confirmation of the ZnO capped ZnSMn was done by TEM and X ray diffraction (XRD).The test band distance is measured using the UV Visible absorption characteristics. Measurement of the dielectric constant is done using the LCR meter

Microstructure and Magnetic Properties of CoFeHfO Rich Nanocrystalline Thin Films Application for High Frequency

2007 ◽  
Vol 558-559 ◽  
pp. 975-978
Author(s):  
L.V. Tho ◽  
K.E. Lee ◽  
Cheol Gi Kim ◽  
Chong Oh Kim ◽  
W.S. Cho
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Magnetic Properties ◽  
Rf Sputtering ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Soft Magnetic ◽  
Electrical And Magnetic Properties ◽  
Transmission Electron ◽  
Nanocrystalline Thin Films

Nanocrystalline CoFeHfO thin films have been fabricated by RF sputtering method. Co52Fe23Hf10O15 thin film is observed, exhibit good magnetic properties with magnetic coercivity (Hc) of 0.18 Oe; anisotropy fild (Hk) of 49 Oe; saturation magnetization (4лMs) of 21 kG, and electrical resistivity (ρ) of 300 01cm. The frequency response of permeability of the film is excellent. The effect of microstructure on the electrical and magnetic properties of thin film was studied using X-ray diffraction (XRD) analysis and conventional transmission electron microscopy (TEM). The results showed that excellent soft magnetic properties were associated with granular nannoscale grains of α-CoFe and α-Co(Fe) phases.

Synthesis and Magnetic Properties of FePt /Silica Core-Shell Nanoparticles

2010 ◽  
Vol 178 ◽  
pp. 291-295 ◽  
Author(s):  
Cui Xia Li ◽  
Zhi Hong Li ◽  
Xue Yan Du ◽  
Hai Xia Guo
Keyword(s):  
Magnetic Properties ◽  
Reverse Micelles ◽  
Core Shell ◽  
Fept Nanoparticles ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Shell Nanoparticles ◽  
Transmission Electron ◽  
Face Centered ◽  
Core Shell Nanoparticles

FePt nanoparticles (NPS), ~2nm in diameter, were synthesized and then coated with silica (SiO2) shells ~1.5nm-thick using reverse micelles as nanoreactors. The silica-coated FePt core–shell (FePt @silica) NPS were characterized by direct techniques of transmission electron microscopy (TEM). The results showed that the silica shells prevented the aggregation in liquid comparing to their bare counterparts. The as-synthesized FePt@SiO2 NPS exhibited essential characteristics of superparamagnetic behavior, as investigated by a vibrating sample magnetometer (VSM). X-ray diffraction (XRD) studies proved that the annealing at 700 °C for 30min under argon atmosphere caused the crystal structure of FePt core to transform from disordered face centered cubic (fcc) to the chemically ordered L10 FePt with face-centered tetragonal (fct) structure. This phase transition caused the change of magnetic properties of the FePt@SiO2 particles from superparamagnetism to ferromagnetism.

Structure of Fe-Based Metallic Glass after Crystallization Process

2010 ◽  
Vol 163 ◽  
pp. 165-168 ◽  
Author(s):  
Ryszard Nowosielski ◽  
Rafał Babilas ◽  
Grzegorz Dercz ◽  
Lucjan Pająk
Keyword(s):  
Magnetic Properties ◽  
Metallic Glass ◽  
Structural Changes ◽  
Crystallization Process ◽  
X Ray Diffraction ◽  
Soft Magnetic ◽  
After Effects ◽  
Transmission Electron ◽  
Saturation Induction

The work presents a crystallization process of Fe-based amorphous alloy by characterization of the influence of annealing temperature on structural changes and magnetic properties of Fe72B20Si4Nb4 metallic glass. The studies were performed on the samples in the form of ribbons and rods. Crystallization behaviour of the studied alloy was examined by X-ray diffraction (XRD) and transmission electron microscopy (TEM) methods. The studies of soft magnetic properties of tested material involved magnetic permeability, saturation induction, coercive field and magnetic after-effects measurements.

Synthesis and Characterization of Structure Controlled Nano-cobalt Particles

2002 ◽  
Vol 755 ◽  
Author(s):  
Shiqiang Hui ◽  
Mingzhong Wu ◽  
Shihui Ge ◽  
Dajing Yan ◽  
Y.D. Zhang ◽  
...  
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Silica Coating ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Average Grain Size ◽  
Wet Chemical ◽  
Face Centered

ABSTRACTNanostructured cobalt particles with and without a ceramic coating have been synthesized using a wet chemical method. The structure and magnetic properties of synthesized powder were characterized using x-ray diffraction (“XRD”), high-resolution transmission electron microscopy (“HRTEM”), and a Quantum Design (SQUID) magnetometer. The cobalt nanoparticles are of either face-centered cubic (“fcc”) and/or hexagonally close-packed (“hcp”) crystalline structures. The average grain size is ∼14 nm for cobalt (either fcc or hcp) with an amorphous silica coating, and the average grain size is ∼9 nm for hcp cobalt and 26 nm for fcc cobalt without a silica coating. The effect of annealing temperature on grain size and magnetic properties are addressed.

Structure and Magnetic Properties Investigation of CoZr and CoZrN Thin Films

2013 ◽  
Vol 464 ◽  
pp. 83-88
Author(s):  
Jitendra Singh ◽  
Arvind K. Singh ◽  
Sanjeev K. Gupta ◽  
J. Akhtar
Keyword(s):  
Magnetic Properties ◽  
Film Thickness ◽  
Nitrogen Content ◽  
X Ray Diffraction ◽  
Soft Magnetic ◽  
Film Properties ◽  
Composite Matrix ◽  
High Electrical Resistivity ◽  
Transmission Electron ◽  
Transmission Electron Microscope Study

nanocomposite [(Co91.5Zr8.5)- or CZN films has been prepared by reactive co-sputter deposition method. Nitrogen content plays key role to tune soft magnetic properties. Experimental observation shows that, non-magnetic nitrogen content enhances magnetization and reduces coercivity. The nanostructure is composed of Co nanoclusters embedded in CoN/ZrN matrix, revealed by high resolution transmission electron microscope study. The d-spacing of single Co nanocluster was found to be ~0.22nm corresponding to (002) phase of Cobalt. X-ray diffraction result is in agreement with cubic (400) and (622) phase of CoZr. High electrical resistivity ρs~108μΩ-cm attained corresponding to 16% N2content films. Hysteresis loop squareness depends on film thickness and coercivity squareness (S*)~0.84, obtained for ~250nm film thickness. A correlated composite nanostructure evolution is responsible for nitrogen induced magnetization and, suggests that film properties can tuned by controlling nitrogen content, in CoN/ZrN composite matrix.

scholarly journals Characterization of ferrite nanoparticles for preparation of biocomposites

2017 ◽  
Vol 8 ◽  
pp. 1257-1265 ◽  
Author(s):  
Urszula Klekotka ◽  
Magdalena Rogowska ◽  
Dariusz Satuła ◽  
Beata Kalska-Szostko
Keyword(s):  
Chemical Method ◽  
Ferrite Nanoparticles ◽  
Chemical Activity ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
Wet Chemical Method ◽  
X Ray ◽  
Transmission Electron ◽  
Wet Chemical

Ferrite nanoparticles with nominal composition Me0.5Fe2.5O4 (Me = Co, Fe, Ni or Mn) have been successfully prepared by the wet chemical method. The obtained particles have a mean diameter of 11–16 ± 2 nm and were modified to improve their magnetic properties and chemical activity. The surface of the pristine nanoparticles was functionalized afterwards with –COOH and –NH2 groups to obtain a bioactive layer. To achieve our goal, two different modification approaches were realized. In the first one, glutaraldehyde was attached to the nanoparticles as a linker. In the second one, direct bonding of such nanoparticles with a bioparticle was studied. In subsequent steps, the nanoparticles were immobilized with enzymes such as albumin, glucose oxidase, lipase and trypsin as a test bioparticles. The characterization of the nanoparticles was acheived by transmission electron microscopy, X-ray diffraction, energy dispersive X-ray and Mössbauer spectroscopy. The effect of the obtained biocomposites was monitored by Fourier transform infrared spectroscopy. The obtained results show that in some cases the use of glutaraldehyde was crucial (albumin).

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