EFFECT OF SAMARIUM DOPING ON THE STRUCTURAL AND MAGNETIC PROPERTIES OF THE LITHIUM–NICKEL FERRITE

2008 ◽  
Vol 22 (21) ◽  
pp. 2027-2033 ◽  
Author(s):  
LUNHONG AI ◽  
JING JIANG ◽  
HEJUN GAO
Keyword(s):  
Magnetic Properties ◽  
Nickel Ferrite ◽  
Spinel Phase ◽  
Lattice Parameter ◽  
Particle Sizes ◽  
Vibrating Sample Magnetometer ◽  
Soft Chemistry ◽  
X Ray ◽  
Transmission Electron ◽  
Structural And Magnetic Properties

Sm -doped Li – Ni ferrites were synthesized by a soft chemistry method. The effects of Sm -doping on the structural and magnetic properties of the Li – Ni ferrites were investigated. The structural, morphological and magnetic properties of the ferrite samples were characterized by X-ray diffractometer (XRD), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). The results revealed that the Sm -doped samples had the single spinel phase at low Sm content. The increase in Sm content increased the lattice parameter and decreased the particle sizes. The magnetic properties of the Sm -doped Li – Ni ferrites were strongly affected by Sm content. The saturation magnetization decreased, while coercivity increased with increasing Sm content.

scholarly journals Evolution of the Structural and Magnetic Properties of Bulk Fe61Co10B20W1Y8−XPtx Alloys through the Partial Substitution of Pt for Y

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4962
Author(s):  
Pawel Pietrusiewicz ◽  
Marcin Nabiałek ◽  
Bartłomiej Jeż
Keyword(s):  
Magnetic Properties ◽  
Small Addition ◽  
Partial Substitution ◽  
Vibrating Sample Magnetometer ◽  
Chemical Formula ◽  
X Ray ◽  
Saturation Magnetisation ◽  
Structural And Magnetic Properties ◽  
Structural Research ◽  
Scanning Electron

This paper presents the results of an investigation into rapidly quenched Fe-based alloys with the chemical formula: Fe61Co10B20W1Y8−xPtx (where x = 3, 4, 5). In these alloys, a small quantity of Pt was added, and the Y content was reduced concurrently. Samples of the aforementioned alloys were injection-cast in the form of plates with the dimensions: 0.5 mm × 10 mm × 10 mm. The resulting structure was examined using X-ray diffractometry (XRD), Mössbauer spectroscopy and scanning electron microscopy (SEM). The results of the structural research reveal that, with a small addition of Pt, areas rich in Pt and Y are created—in which Fe-Pt and Pt-Y compounds, with different crystallographic systems, are formed. It has also been shown that an increase in Pt content, at the expense of Y, contributed to the formation of fewer crystalline phases, i.e., it allowed a material with a more homogeneous structure to be obtained. Magnetic properties of the Fe61Co10B20W1Y8−xPtx (where x = 3, 4, 5) alloy samples were tested using a vibrating sample magnetometer (VSM). The magnetic properties of the investigated materials revealed that the saturation magnetisation increased with increasing Pt content, at the expense of Y. This effect is due to the occurrence of different proportions of crystalline magnetic phases within the volume of each alloy.

Nickel Ferrite: Combustion Synthesis, Characterization and Magnetic Properties

2005 ◽  
Vol 498-499 ◽  
pp. 618-623 ◽  
Author(s):  
Ana Cristina Figueiredo de Melo Costa ◽  
Lucianna Gama ◽  
M.R. Morelli ◽  
Ruth Herta Goldsmith Aliaga Kiminami
Keyword(s):  
Magnetic Properties ◽  
Nickel Ferrite ◽  
High Speed ◽  
High Specific Surface Area ◽  
Line Broadening ◽  
X Ray Diffraction ◽  
X Ray ◽  
Railway Systems ◽  
Transmission Electron ◽  
Dry Pressing

Nanosized spinel nickel ferrite particles have attracted considerable attention and efforts continue to investigate them for their technological importance to the microwave industries, high speed digital tap or disk recording, repulsive suspension for use in levitated railway systems, ferrofluids, catalysis and magnetic refrigeration systems. Nanosize nickel ferrite powders (NiFe2O4) have been prepared by combustion reaction using nitrates and urea as fuel. The resulting powders were characterized by X-ray diffraction (XRD), BET, and transmission electron microscopy (TEM). The results showed nanosize nickel ferrite powders with high specific surface area (55.21 m2/g). The powders showed extensive XRD line broadening and the crystallite size calculated from the XRD line broadening was 18.0 nm. The samples were uniaxially compacted by dry pressing, sintered at 1200°C/2h and characterized by bulk density, SEM and magnetic properties measurements. The samples showed uniform microstructures with grain size of 4.45 μm, maximum flux density of 0.18T, field coercive of the 488 A/m, and hysteresis loss of 47.58 W/kg.

ZnFe2O4 Modified by Fe(NO3)3 for the Synthesis of Ionic Ferrofluids

2010 ◽  
Vol 177 ◽  
pp. 32-36 ◽  
Author(s):  
An Rong Wang ◽  
Jian Li ◽  
Qing Mei Zhang ◽  
Hua Miao
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Photoelectron Spectroscopy ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Znfe2o4 Nanoparticles

Weak magnetic ZnFe2O4 nanoparticles were prepared by coprecipitation and treated with different concentrations of Fe(NO3)3 solution. Untreated and treated particles were studied using a vibrating sample magnetometer, transmission electron microscope, by X-ray diffraction, X-ray energy dispersive spectroscopy and X photoelectron spectroscopy. The results showed that, after treatment, the ZnFe2O4/γ-Fe2O3 forms disphase nanoparticles, with enlarged size, enhanced magnetic properties and with a surface parceled with Fe(NO3)3. The size of the particles and their magnetic properties are related to the concentration of the treatment solution. The particle size and magnetic properties could be controlled by controlling the concentration of treating solution, therefore nanoparticles can be more widely used.

Preparation of Hollow Nickel Ferrite Microspheres and their Magnetic Properties

2014 ◽  
Vol 1035 ◽  
pp. 488-491
Author(s):  
Jing Jing Li ◽  
Yun Zhao ◽  
Han Sheng Li ◽  
Qin Wu ◽  
Qing Ze Jiao
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Nickel Ferrite ◽  
Room Temperature ◽  
Solvothermal Method ◽  
Magnetization Measurement ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Hollow nickel ferrite microspheres with a diameter of about 1.5 to 2.5 μm were synthesized using an emulsion-based solvothermal method in combination with calcination at 550°C. The structures and morphologies of the nickel ferrite microspheres were characterized using an X-ray diffractometer, a transmission electron microscopy and a field emission scanning electron microscopy. Magnetization measurement was carried out using a vibrating sample magnetometer at room temperature. The saturation magnetization and coercivity of nickel ferrite microspheres could reach 19.41 emu/g and 202.28 Oe, respectively. Hollow nickel ferrite microspheres might be used as catalysts, magnetic materials and microwave absorbers.

Structural and Magnetic Properties of Epitaxial Co-Au Superlattices

1989 ◽  
Vol 151 ◽  
Author(s):  
C. H. Lee ◽  
Hui He ◽  
F. Lamelas ◽  
W. Vavra ◽  
C. Uher ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Molecular Beam ◽  
Easy Axis ◽  
Constant Thickness ◽  
Substrate Plane ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Axis Parallel ◽  
Structural And Magnetic Properties

ABSTRACTWe describe measurements on the structural and magnetic properties of Co–Au superlattices grown on Ge–buffered (110) GaAs by molecular beam epitaxy. Samples have been prepared with Co layer thicknesses ranging from 5–40Å and Au spacer layers of constant thickness, ∼ 16Å. X–ray scattering and high-resolution transmission electron microscopy show that the hcp Co layers grow epitaxially with the (0001) axis parallel to (111)Au and with the in–plane Co[1120] axis parallel to GaAs[001]. SQUID magnetometer measurements reveal a crossover in the magnetic anisotropy of the as–grown samples such that the easy axis is perpendicular to the substrate plane when the Co layer thickness is less than ∼19Å.

Synthesis and Magnetic Properties of CoFe2O4 Nano-Particles

2010 ◽  
Vol 148-149 ◽  
pp. 998-1002 ◽  
Author(s):  
Xiao Yun Chen ◽  
Hua Li ◽  
Yue Zeng Su ◽  
Zi Shan Huang ◽  
He Zhou Liu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Properties ◽  
Hydrothermal Process ◽  
Nano Particles ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Water Ratio

Spinel CoFe2O4 nano-particles were synthesized by hydrothermal traditionally and Ethylene Glycol (EG) assisted hydrothermal process originally. The effects of reaction temperatures from 140°C to 200°C, different OH- provider and EG/water ratio on the nano-particles’ structure, morphology and magnetic properties of composition were studied by X-ray diffractometer (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The possible mechanism for the effects on the properties was also discussed in details. The results showed that NaAC as OH- provider and higher EG/water ratio in solvent were benefit for getting smaller CoFe2O4 nano-particles. And existence of EG is also important to remove the α-Fe2O3 phase.

scholarly journals Sintesis Nanopartikel Nickel Ferrite (NiFe2O4) dengan Metode Kopresipitasi dan Karakterisasi Sifat Kemagnetannya (Halaman 20 s.d. 25)

2015 ◽  
Vol 19 (56) ◽  
Author(s):  
Muflihatun ◽  
Siti Shofiah ◽  
Edi Suharyadi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fourier Transform ◽  
Nickel Ferrite ◽  
Fourier Transform Infrared ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

Nanopartikel Nikel Ferit (NiFe2O4) telah disintesis dengan metode kopresipitasi dengan memvariasi konsentrasi NaOH dan suhu sintesis. Struktur kristal, ukuran partikel, dan morfologi dari sampel dianalisa menggunakan X-ray diffraction (XRD) dan transmission electron microscopy (TEM). Ukuran butir pada konsentrasi NaOH 3, 5, dan 10 M masing-masing adalah 5,7; 4,3; dan 4,2 nm, sedangkan pada suhu 60, 80, dan 150°C berturut-turut adalah 4,2; 4,9; dan 5,5 nm. Analisa fourier transform infrared (FTIR) menunjukkan dua puncak serapan pada rentang ~400-600 cm-1 yang terkait dengan site oktahedral dan tetrahedral pada struktur NiFe2O4. Sifat magnetik NiFe2O4 hasil analisa vibrating sample magnetometer (VSM) menunjukkan bahwa sampel berperilaku ferromagnetik dengan nilai koersivitasnya pada rentang 42-47 Oe. Sampel dengan variasi konsentrasi NaOH, koersivitasnya cenderung menurun dengan menurunnya ukuran partikel. Sementara sampel dengan variasi suhu, semakin kecil ukuran partikel, koersivitasnya cenderung meningkat. Pada 15 kOe, nilai magnetisasi terbesar (6,17 emu/g) diperoleh pada sampel dengan rasio fasa α-Fe2O3 paling rendah.

MAGNETIC PROPERTIES OF Co-FERRITE AND SiO2-DOPED Co-FERRITE THIN FILMS AND POWDERS BY SOL–GEL

2004 ◽  
Vol 03 (04n05) ◽  
pp. 463-470
Author(s):  
Y. C. WANG ◽  
J. DING ◽  
B. H. LIU ◽  
Y. SHI
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Structural And Magnetic Properties ◽  
Ferrite Thin Films ◽  
Scanning Electron

Thin films and powders of Co -ferrite and SiO 2-doped Co -ferrite were fabricated via the sol–gel method. The structural and magnetic properties of the films and powders were investigated with X-Ray Diffractometer (XRD), Vibrating Sample Magnetometer (VSM), Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). VSM measurements showed an enhancement of coercivity by SiO 2-doping for Co -ferrite powders and thin films (coercivity of 3.5 kOe in SiO 2-doped thin films). XRD and SEM investigations revealed a nanostructure of the thin films. Low surface roughness was observed in our AFM study.

STRUCTURE AND MAGNETIC PROPERTIES OF CARBON-ENCAPSULATED Fe NANOPARTICLES OBTAINED BY A MODIFIED ARC PLASMA METHOD

2009 ◽  
Vol 23 (17) ◽  
pp. 2149-2153 ◽  
Author(s):  
GUIZHEN WANG ◽  
GENGPING WAN ◽  
CHUNCHENG HAO
Keyword(s):  
Magnetic Properties ◽  
Magnetic Measurements ◽  
Carbon Sources ◽  
Vibrating Sample Magnetometer ◽  
Arc Plasma ◽  
X Ray ◽  
Plasma Method ◽  
Transmission Electron ◽  
Fe Nanoparticles ◽  
Coating Layers

Carbon-encapsulated Fe nanoparticles were synthesized by a modified arc plasma method using methane and starch as carbon sources, respectively. The particles were characterized in detail by transmission electron microscope and X-ray powder diffraction. They are somewhat spherical in shape and the coating layers of the two sample types are composed of amorphous carbon. Magnetic measurements using a vibrating sample magnetometer demonstrate that the prepared composites have different magnetic properties.

STRUCTURAL AND MAGNETIC PROPERTIES OF THE THIN FILM OF COBALT NITRIDE

2014 ◽  
Vol 21 (06) ◽  
pp. 1450081 ◽  
Author(s):  
ZOHRA NAZIR KAYANI ◽  
SAIRA RIAZ ◽  
SHAHZAD NASEEM
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Magnetic Memory ◽  
Vibrating Sample Magnetometer ◽  
Orthorhombic Structure ◽  
X Ray ◽  
Cu Substrates ◽  
Gel Technique ◽  
Structural And Magnetic Properties ◽  
Memory Applications

Cobalt nitride has been prepared and studied for magnetic memory applications. Sol–gel technique is used to prepare thin films of cobalt nitride. The films were deposited onto Cu substrates by spin coating at 3000 rpm for 30 s. The films were then air dried and heated at 300°C for 120 min. As-deposited and heated samples were characterized for their structural and magnetic properties using X-ray diffractometer (XRD) and vibrating sample magnetometer (VSM) techniques. The grain size was in the range of 22.7–30.10 nm. Their surface was studied by scanning electron microscopy (SEM). Orthorhombic structure can be seen in SEM micrographs. This orthorhombic structure is also confirmed by XRD.

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