scholarly journals Magnetic properties of ND Rich Melt-Spun ND-FE-B alloy

2005 ◽  
Vol 37 (2) ◽  
pp. 139-145 ◽  
Author(s):  
Aleksandar Grujic ◽  
Nadezda Talijan ◽  
Aleksa Maricic ◽  
Jasna Stajic-Trosic ◽  
Vladan Cosovic ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Measurement ◽  
Rapid Quenching ◽  
Experimental Investigations ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Information ◽  
Melt Spun ◽  
Quenching Process ◽  
Rich Content

As a part of these experimental investigations of melt-spun Nd-Fe-B alloy with Nd rich content in relation to Nd2Fe14B prepared by rapid quenching process for optimally selected cooling rate and heat treatment, the influence of the chosen chemical composition on magnetic properties was observed. The results of X-ray diffraction, M?ssbauer spectroscopy phase analysis and magnetic measurement of investigated melt-spun Nd14.5Fe78.5B7 alloy are presented to bring some new information concerning the relation between their structure and magnetic properties.

EFFECT OF NANOCRYSTALLIZATION ANNEALING ON MAGNETIC PROPERTIES AND MAGNETOIMPEDANCE OF CO-BASE RIBBONS

2012 ◽  
Vol 05 ◽  
pp. 841-846
Author(s):  
AMIR KEYVANARA ◽  
REZA GHOLAMIPOUR ◽  
SHAMSEDIN MIRDAMADI ◽  
FARZAD SHAHRI ◽  
HOSSEIN SEPEHRI AMIN
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Magnetic Properties ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Melt Spun ◽  
Melt Spun Ribbons ◽  
Nanocrystalline Phases

Melt spun ribbons of Co 64 Fe 4 Ni 2 B 19 Si 8 Cr 3 alloy have been prepared and the nanocrystallization process was carried out by the heat treatment of the as spun ribbons above the crystallization temperature. Structural studies of the samples have been performed by transmission electron microscopy and X-ray diffraction. Magnetic properties of the samples and magnetoimpedance measurements were investigated and it was revealed that magnetic properties and magnetoimpedance of the samples deteriorate by the formation of nanocrystalline phases.

scholarly journals Effect of Titanium Substitution on Magnetic Properties and Microstructure of Nanocrystalline Monophase Nd-Fe-B Magnets

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Wang Cong ◽  
Guo ZhiMeng ◽  
Sui YanLi ◽  
Bao XiaoQian ◽  
Chen ZhiAn
Keyword(s):  
Magnetic Properties ◽  
Crystallization Process ◽  
Annealing Treatment ◽  
Rapid Quenching ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Ti Substitution ◽  
Ti Addition ◽  
Titanium Substitution

Nd12.3Fe81.7−xTixB6.0  (x=0.5–3.0)ribbons have been prepared by rapid quenching and subsequent annealing treatment. Effect of Ti substitution and annealing treatment on the microstructure, magnetic properties, and crystallization behavior of the ribbons was systematically investigated by the methods of differential scanning calorimeter (DSC), X-ray diffraction (XRD), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM). It is found that Ti addition may increase the crystallization temperature and stabilize the amorphous phase. Ti element inhibits the grain growth during crystallization process and finally refines the microstructure. The exchange coupling interactions and magnetic properties of the ribbons increase with increasingxfrom 0.5 to 1 and then decrease with further increasingx≥1.5. Optimum magnetic properties with(BH)max⁡=151.6 kJ/m3,Hci=809.2 kA/m,Jr=1.02 T are achieved in the Nd12.3Fe80.7Ti1B6.0ribbons annealed at 600°C for 10 min.

scholarly journals Improvement of the Magnetic Properties of Nanocrystalline Nd12.3(FeZrNbCu)81.7B6.0Alloys with Dy Substitutions

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Weiwei Yang ◽  
Leichen Guo ◽  
Zhimeng Guo ◽  
Guangle Dong ◽  
Yanli Sui ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Exchange Coupling ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Material Microstructure ◽  
X Ray ◽  
Maximum Value ◽  
Transmission Electron ◽  
Melt Spun ◽  
Melt Spun Ribbons

Nd12.3−xDyxFe81.7Zr0.8Nb0.8Cu0.4B6.0  (x=0–2.5)ribbons have been prepared by melt-spun at 30 m/s and subsequent annealing. The influence of addition of Dy on the crystallization behavior, magnetic properties, and microstructure were investigated. Differential scanning calorimeter (DSC) and X-ray diffraction (XRD) revealed a single-phase material. Microstructure studies using transmission electron microscopy (TEM) had shown a significant microstructure refinement with Dy addition. Wohlfarth’s analysis showed that the exchange coupling interactions increased first with Dy contentxincreasing, reached the maximum value atx=0.5, and then slightly decreased withxfurther increasing. Optimal magnetic properties withJr=1.09 T,Hci=1048 kA/m, andBHmax=169.5 kJ/m3are achieved by annealing the melt-spun ribbons withx=0.5at% at 700°C for 10 min.

Anomalous X-ray Scattering Study of the Quasi-crystalline Al65Cu20Fe15 Alloy

1990 ◽  
Vol 45 (1) ◽  
pp. 50-54 ◽  
Author(s):  
E. Matsubara ◽  
Y. Waseda
Keyword(s):  
Experimental Information ◽  
Rapid Quenching ◽  
Distribution Functions ◽  
Radial Distribution Functions ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Quenching Process ◽  
Scattering Study ◽  
Ray Scattering

AbstractThe environmental radial distribution functions (RDFs) around Cu and Fe as well as the ordinary RDF of an as-quenched Al65Cu20Fe15 alloy have been determined by anomalous x-ray scattering (AXS) and conventional x-ray diffraction techniques. The experimental information indicates that a strong directional dependence along the symmetrical axes exists for the Cu atoms but not for the Fe atoms. Almost identical RDFs were also obtained in both the as-quenched and fully-annealed states of the Al65Cu20Fe15 alloy. Thus, the small differences observed between diffraction profiles of the as-quenched and annealed samples of this alloy may be attributed to defects or strains introduced during the rapid quenching process.

Optimization of Structure and Magnetic Properties of NdFeBTi Nanocomposite Magnets

2012 ◽  
Vol 186 ◽  
pp. 206-211
Author(s):  
Daniela Derewnicka ◽  
Piotr Dłużewski ◽  
Marzena Spyra ◽  
Hanna Krztoń
Keyword(s):  
Magnetic Properties ◽  
Phase Composition ◽  
Electron Microscope ◽  
Amorphous Ribbon ◽  
Annealing Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nanocomposite Magnets ◽  
Transmission Electron ◽  
Melt Spun

This study investigated alloys with the composition Nd9Fe77B14 and Nd9Fe73Ti4B14 (at.%). Materials were melt spun in the form of a partially amorphous ribbon, which was subsequently annealed at 953K in order to obtain the optimum magnetic properties. The highest properties were obtained for annealing lasting 20 minutes (JHC = 913kA/m, Jr = 0,84T, BHmax = 107kJ/m3). Annealing at 953K results in simultaneous crystallisation in the whole mass of the alloy. The growth of grains is controlled by the duration of the annealing process. The objective of this work was to study the mechanisms of crystallisation and the reasons for a finer structure resulting from the presence of titanium. The phase composition was evaluated by X-ray diffraction. The microstructure was studied using a high-resolution transmission electron microscope. Detailed analysis of titanium distribution in the grains and in the grain boundaries was examined by x-ray spectrometry.

X-ray microprobe for materials science

1994 ◽  
Vol 52 ◽  
pp. 56-57
Author(s):  
G.E. Ice
Keyword(s):  
Crystallographic Orientation ◽  
Local Structure ◽  
Materials Science ◽  
Chemical Information ◽  
X Ray Diffraction ◽  
Ray Optics ◽  
X Ray ◽  
Novel Materials ◽  
New Information ◽  
Elemental Sensitivity

The increasing availability of synchrotron x-ray sources has stimulated the development of advanced hard x-ray (E≥5 keV) microprobes. With new x-ray optics these microprobes can achieve micron and submicron spatial resolutions. The inherent elemental and crystallographic sensitivity of an x-ray microprobe and its inherently nondestructive and penetrating nature will have important applications to materials science. For example, x-ray fluorescent microanalysis of materials can reveal elemental distributions with greater sensitivity than alternative nondestructive probes. In materials, segregation and nonuniform distributions are the rule rather than the exception. Common interfaces to whichsegregation occurs are surfaces, grain and precipitate boundaries, dislocations, and surfaces formed by defects such as vacancy and interstitial configurations. In addition to chemical information, an x-ray diffraction microprobe can reveal the local structure of a material by detecting its phase, crystallographic orientation and strain.Demonstration experiments have already exploited the penetrating nature of an x-ray microprobe and its inherent elemental sensitivity to provide new information about elemental distributions in novel materials.

scholarly journals Green synthesis and characterization of hexaferrite strontium-perovskite strontium photocatalyst nanocomposites

2020 ◽  
Vol 43 (1) ◽  
pp. 26-42 ◽  
Author(s):  
Zahra Hajian Karahroudi ◽  
Kambiz Hedayati ◽  
Mojtaba Goodarzi
Keyword(s):  
Magnetic Properties ◽  
Green Synthesis ◽  
Sol Gel ◽  
Synthesis Method ◽  
Combustion Method ◽  
Lemon Juice ◽  
X Ray Diffraction ◽  
X Ray ◽  
Auto Combustion

AbstractThis study presents a preparation of SrFe12O19– SrTiO3 nanocomposite synthesis via the green auto-combustion method. At first, SrFe12O19 nanoparticles were synthesized as a core and then, SrTiO3 nanoparticles were prepared as a shell for it to manufacture SrFe12O19–SrTiO3 nanocomposite. A novel sol-gel auto-combustion green synthesis method has been used with lemon juice as a capping agent. The prepared SrFe12O19–SrTiO3 nanocomposites were characterized by using several techniques to characterize their structural, morphological and magnetic properties. The crystal structures of the nanocomposite were investigated via X-ray diffraction (XRD). The morphology of SrFe12O19– SrTiO3 nanocomposite was studied by using a scanning electron microscope (SEM). The elemental composition of the materials was analyzed by an energy-dispersive X-ray (EDX). Magnetic properties and hysteresis loop of nanopowder were characterized via vibrating sample magnetometer (VSM) in the room temperature. Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed the molecular bands of nanoparticles. Also, the photocatalytic behavior of nanocomposites has been checked by the degradation of azo dyes under irradiation of ultraviolet light.

scholarly journals Influence of Li2CO3 addition on electrical and magnetic properties of Ni0.6Mg0.4Fe2O4

2020 ◽  
Vol 10 (03) ◽  
pp. 2050003
Author(s):  
M. R. Hassan ◽  
M. T. Islam ◽  
M. N. I. Khan
Keyword(s):  
Magnetic Properties ◽  
Single Phase ◽  
Low Frequency ◽  
Solid State Reaction Method ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrical And Magnetic Properties ◽  
Frequency Regime ◽  
Xrd Patterns

In this research, influence of adding Li2CO3 (at 0%, 2%, 4%, 6%) on electrical and magnetic properties of [Formula: see text][Formula: see text]Fe2O4 (with 60% Ni and 40% Mg) ferrite has been studied. The samples are prepared by solid state reaction method and sintered at 1300∘C for 6[Formula: see text]h. X-ray diffraction (XRD) patterns show the samples belong to single-phase cubic structure without any impurity phase. The magnetic properties (saturation magnetization and coercivity) of the samples have been investigated by VSM and found that the higher concentration of Li2CO3 reduces the hysteresis loss. DC resistivity increases with Li2CO3 contents whereas it decreases initially and then becomes constant at lower value with temperature which indicates that the studied samples are semiconductor. The dielectric dispersion occurs at a low-frequency regime and the loss peaks are formed in a higher frequency regime, which are due to the presence of resonance between applied frequency and hopping frequency of charge carriers. Notably, the loss peaks are shifted to the lower frequency with Li2CO3 additions.

Effect of Nitridation Magnetic Properties of Nanocrystalline Fe-Co Alloy Powders

2010 ◽  
Vol 654-656 ◽  
pp. 1106-1109
Author(s):  
Ya Qiong He ◽  
Chang Hui Mao ◽  
Jian Yang
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Alloy Powder ◽  
High Energy ◽  
X Ray Diffraction ◽  
Powder Mixtures ◽  
X Ray ◽  
Transmission Electron ◽  
Nitridation Temperature ◽  
Microstructure And Magnetic Properties

Nanocrystalline Fe-Co alloy powders, which were prepared by high-energy mechanical milling, were nitrided under the mixing gas of NH3/H2 in the temperature range from 380°C to 510°C. X-ray diffraction (XRD) was used to analyze the grain size and reaction during the processing. The magnetic properties of the nitrided powders were measured by Vibrating Sample Magnetometer (VSM). The results show that with the appearance of Fe4N phase after nitride treatment, and the grain-size of FeCo phase decreases with the increase of nitridation temperature between 380°C to 450°C.The saturation magnetization of nitrided alloy powder treated at 480°C is about 18% higher than that of the initial Fe-Co alloy powder, accompanied by the reduction of the coercivity. Transmission electron microscope (TEM) was used, attempting to further analyze the effect of Fe4N phase on microstructure and magnetic properties of the powder mixtures.

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