Mechanochemical Synthesis of Nanocrystalline (Fe,Co)3О4-Based Alloys and their Magnetic Properties

2011 ◽  
Vol 170 ◽  
pp. 97-101 ◽  
Author(s):  
Vladimir P. Menushenkov ◽  
Yurii D. Yagodkin ◽  
Ekaterina Shandrovskaiy
Keyword(s):  
Magnetic Properties ◽  
Crystallite Size ◽  
High Energy ◽  
Hard Alloys ◽  
X Ray Diffraction ◽  
Low Temperature Annealing ◽  
Transmission Electron ◽  
Energy Ball ◽  
Magnetically Hard ◽  
Nanocrystalline Composite

The structure of nanocrystalline Fe-Co-O alloys produced by high-energy ball milling and subsequent low-temperature annealing were investigated by X-ray diffraction analysis, scanning and transmission electron microscopy. The magnetic properties were measured in vibrating sample magnetometers at room temperature. The mixtures of FeO and Co powders were used as starting materials. The nanocrystalline composite alloys, obtained as a result of the milling, contained FeO and -Fe with the crystallite size of 12-18 nm as well as an amorphous phase. However, alloys subjected to subsequent annealing contained Fe3O4 and -Fe phases with crystallite size of 10-30 nm, in which Co is dissolved. Unlike the starting materials the produced powders exhibit properties typical of magnetically hard alloys. The intrinsic coercive force of the annealed powders increases with increasing (Fe,Co)3O4 phase content and reaches approximately 800 Oe.

Structure and Magnetic Properties of Ternary Nanosized FeAlSn and CuFeCo Powders Synthesized by Mechanical Milling

2017 ◽  
Vol 47 ◽  
pp. 79-88 ◽  
Author(s):  
Z. Hamlati ◽  
W. Laslouni ◽  
Mohammed Azzaz ◽  
M. Zergoug ◽  
D. Martínez-Blanco ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Crystallite Size ◽  
Milling Time ◽  
Magnetic Measurements ◽  
High Energy ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
High Energy Ball Mill ◽  
Powder Particles ◽  
Energy Ball

Ternary Fe72Al26Sn2 and Cu70Fe18Co12 alloys were obtained by mechanical alloying of pure Fe, Al, Sn, Cu and Co powders using a high energy ball mill. X-ray diffraction and electron microscopy supported by magnetic measurements have been applied to follow changes in the microstructure, phase composition and magnetic properties in dependence on milling time. With the increase of milling time all Al and Sn atoms dissolved in the bcc Fe and the final product of the MA process was the nanocrystalline Fe (Al, Sn) solid solution in a metastable state with a large amount of defects and mean crystallite size of 5 nm. However, the obtained crystallite size value is about 10 nm for the ball milled Cu70Fe18Co12 powders. The electron microscope observations show the morphology of powder particles. Magnetic properties of the nanocrystalline mechanically alloyed FeAlSn and CuFeCo were also investigated and were related to the microstructural changes.

scholarly journals Effects of Recycled Fe2O3 Nanofiller on the Structural, Thermal, Mechanical, Dielectric, and Magnetic Properties of PTFE Matrix

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2332
Author(s):  
Ahmad Mamoun Khamis ◽  
Zulkifly Abbas ◽  
Raba’ah Syahidah Azis ◽  
Ebenezer Ekow Mensah ◽  
Ibrahim Abubakar Alhaji
Keyword(s):  
Electron Microscopy ◽  
High Energy ◽  
Filler Loading ◽  
Complex Permeability ◽  
X Ray Diffraction ◽  
Thermal Expansion Coefficients ◽  
Transmission Electron ◽  
Energy Ball ◽  
Hematite Fe2o3 ◽  
Ptfe Composites

The purpose of this study was to improve the dielectric, magnetic, and thermal properties of polytetrafluoroethylene (PTFE) composites using recycled Fe2O3 (rFe2O3) nanofiller. Hematite (Fe2O3) was recycled from mill scale waste and the particle size was reduced to 11.3 nm after 6 h of high-energy ball milling. Different compositions (5–25 wt %) of rFe2O3 nanoparticles were incorporated as a filler in the PTFE matrix through a hydraulic pressing and sintering method in order to fabricate rFe2O3–PTFE nanocomposites. The microstructure properties of rFe2O3 nanoparticles and the nanocomposites were characterized through X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and high-resolution transmission electron microscopy (HRTEM). The thermal expansion coefficients (CTEs) of the PTFE matrix and nanocomposites were determined using a dilatometer apparatus. The complex permittivity and permeability were measured using rectangular waveguide connected to vector network analyzer (VNA) in the frequency range 8.2–12.4 GHz. The CTE of PTFE matrix decreased from 65.28×10−6/°C to 39.84×10−6/°C when the filler loading increased to 25 wt %. The real (ε′) and imaginary (ε″) parts of permittivity increased with the rFe2O3 loading and reached maximum values of 3.1 and 0.23 at 8 GHz when the filler loading was increased from 5 to 25 wt %. A maximum complex permeability of 1.1−j0.07 was also achieved by 25 wt % nanocomposite at 10 GHz.

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.

In Situ Analysis of magnetic and Structural Properties of Epitaxial and Polycrystalline Ni80Fe20 Thin Films

1993 ◽  
Vol 313 ◽  
Author(s):  
I. Hashim ◽  
H.A. Atwater ◽  
Thomas J. Watson
Keyword(s):  
Magnetic Properties ◽  
Kerr Effect ◽  
High Energy ◽  
Epitaxial Films ◽  
Interface Roughness ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Transmission Electron

ABSTRACTWe have investigated structural and magnetic properties of epitaxial Ni80Fe20 films grown on relaxed epitaxial Cu/Si (001) films. The crystallographic texture of these films was analyzed in situ by reflection high energy electron diffraction (RHEED), and ex situ by x-ray diffraction and cross-sectional transmission electron Microscopy (XTEM). In particular, RHEED intensities were recorded during epitaxial growth, and intensity profiles across Bragg rods were used to calculate the surface lattice constant, and hence, find the critical epitaxial thickness for which Ni80Fe20 grows pseudomorphically on Cu (100). XTEM analysis indicated that the epitaxial films had atomically-abrupt interfaces which was not the case for polycrystalline Cu and Ni80Fe20 film interfaces. The Magnetic properties of these epitaxial films were Measured in situ using Magneto-optic Kerr effect magnetometry and were compared with those of polycrystalline films grown on SiO2/Si. Large Hc (∼ 35 Oe) was observed for epitaxial Ni80Fe20 films less than 3.0 nm thick whereas for increasing thickness, Hc decreased approximately monotonically to a few Oersteds. Correlations were made between magnetic properties of these epitaxial films, the strain in the film and the interface roughness obtained from XTEM analysis.

Mechanism of Achieving Nanocrystalline AIRu By Ball Milling

1988 ◽  
Vol 132 ◽  
Author(s):  
E. Hellstern ◽  
H. J. Fecht ◽  
C. Garland ◽  
W. L. Johnson ◽  
W. M. Keck
Keyword(s):  
Ball Milling ◽  
Crystal Size ◽  
Shear Bands ◽  
Nanocrystalline Structure ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Energy Ball ◽  
Small Grains

ABSTRACTWe investigated through X- ray diffraction and transmission electron microscopy the crystal refinement of the intermetallic compound AIRu by high- energy ball milling. The deformation process causes a decrease of crystal size to 5–7 rum and an increase of atomic level strain. This deformation is localized in shear bands with a thickness of 0.5 to 1 micron. Within these bands the crystal lattice breaks into small grains with a typical size of 8–14 rum. Further deformation leads to a final nanocrystalline structure with randomly oriented crystallite grains separated by high- angle grain boundaries.

Atmosphere effects of the amorphization reaction in NiZr by ball milling

1993 ◽  
Vol 8 (2) ◽  
pp. 307-313 ◽  
Author(s):  
K. Aoki ◽  
A. Memezawa ◽  
T. Masumoto
Keyword(s):  
High Energy ◽  
Hydrogen Atmosphere ◽  
Nitrogen Atmosphere ◽  
Gas Absorption ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
High Energy Ball Mill ◽  
Energy Ball

An intermetallic compound c–NiZr and a mixture of elemental powders of nickel and zirconium [Ni50Zr50 (at. %)] have been mechanically ground (MG) and mechanically alloyed (MA), respectively, using a high-energy ball mill in various atmospheres. The products were characterized by x-ray diffraction, transmission electron microscopy, differential scanning calorimetry, and chemical analysis as a function of milling time. An amorphous a–NiZr alloy was prepared by both MG and MA in an argon atmosphere. By MG of NiZr, an amorphous nitride a–NiZrN0.15 was synthesized in a nitrogen atmosphere, while a crystalline hydride c–NiZrH3 was formed in a hydrogen atmosphere. On the other hand, ZrN and ZrH2 were formed by MA in a nitrogen and a hydrogen atmosphere, respectively. The amorphization reaction was observed between ZrH2 and Ni by further MA in a hydrogen atmosphere, and a mixture of a–NiZrxHy (x < 1) and ZrH2 was obtained. However, no amorphization was observed by MA between ZrN and Ni in a nitrogen atmosphere. The effects of the milling atmosphere on the phase formations during MG and MA are discussed based on the gas absorption rate.

scholarly journals Structural and Magnetic Properties of Ba3[Cu0.8−xZnxMn0.2]2Fe24O41 Z-Type Hexaferrites

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Eman S. Al-Hwaitat ◽  
Sami H. Mahmood ◽  
Mahmoud Al–Hussein ◽  
Ibrahim Bsoul
Keyword(s):  
Magnetic Properties ◽  
Anisotropy Field ◽  
High Energy ◽  
X Ray Diffraction ◽  
Zn Content ◽  
Energy Ball ◽  
Structural And Magnetic Properties ◽  
Ball Milling Technique ◽  
Xrd Patterns

We report on the synthesis and characterization of Ba3[Cu0.8−xZnxMn0.2]2Fe24O41 (x = 0.0, 0.2, 0.4, 0.6, and 0.8) barium hexaferrites. The samples were prepared by high-energy ball-milling technique and double-sintering approach. The effects of Zn substitution for Cu on the structural and magnetic properties of the prepared samples were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). XRD patterns of the samples revealed the presence of a major Z-type hexaferrite phase, together with secondary M-type and Y-type phases. The magnetic results indicated that the saturation magnetization increased slightly with increasing the Zn content, while the coercivity and magnetocrystalline anisotropy field exhibited a decreasing tendency with the increase of Zn content. The thermomagnetic curves revealed the complex magnetic structure of the prepared samples and confirmed that the Curie temperature of the magnetic phases decreased with increasing x as a result of the reduction of the strength of the superexchange interactions.

Effect of Boron on the Amorphization of Fe-Si Alloys by Mechanical Alloying

2012 ◽  
Vol 730-732 ◽  
pp. 739-744 ◽  
Author(s):  
Petr Urban ◽  
Francisco Gomez Cuevas ◽  
Juan M. Montes ◽  
Jesus Cintas
Keyword(s):  
Electron Microscopy ◽  
Mechanical Alloying ◽  
Alloy System ◽  
High Energy ◽  
Milling Process ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Structural And Phase Transformations ◽  
Transmission Electron ◽  
Energy Ball

The amorphization process by mechanical alloying in the Fe-Si alloy system has been studied. High energy ball milling has been applied for alloys synthesis. X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to monitor the structural and phase transformations through the different stages of milling. The addition of amorphous boron in the milling process and the increase of the milling time were used to improve the formation of the amorphous phase. Heating the samples resulted in the crystallization of the synthesized amorphous alloys and the appearance of equilibrium intermetallic compounds.

Mössbauer and magnetization studies of mechanically milled nanocrystalline Fe1–xAlx alloys

2015 ◽  
Vol 93 (11) ◽  
pp. 1257-1263
Author(s):  
S. Rajan ◽  
R. Shukla ◽  
A. Kumar ◽  
A. Vyas ◽  
S. Khan ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Behavior ◽  
High Energy ◽  
Milling Process ◽  
Transmission Electron ◽  
Bulk Magnetization ◽  
Hyperfine Field Distributions ◽  
Equilibrium Process ◽  
Energy Ball ◽  
Evolution Of Microstructure

Changes in the magnetic behavior of Fe1–xAlx (x = 0.3, 0.4, 0.5, 0.6) powders during mechanical alloying have been studied. The ball milling process leads to formation of solid state reaction assisted by severe plastic deformation because of which crystallite size is reduced and as a result of which interesting magnetic properties are developed. The evolution of magnetic order in high-energy ball-milled Fe–Al solid solution is investigated using 57Fe Mössbauer spectroscopy and vibrating sample magnetometer. Mössbauer spectra and the hyperfine field distributions of all the samples show the presence of both magnetic and paramagnetic components in the samples. The corresponding bulk magnetization studies also show that the Al rich samples are also ferromagnetic, which can be attributed to the presence of disordered Fe-rich phases due to the non-equilibrium process of alloying. In Fe-rich samples, the formation of an off stoichiometric Fe3Al phase is favored while in the case of Al-rich samples both Al-rich phases and clustering of Fe and Al atoms are present. The systematic variation in the magnetic properties has been qualitatively correlated with the evolution of microstructure, reduction in grain size (obtained using transmission electron microscopy) and enhanced intergranular exchange coupling.

The Investigation of Structural and Magnetic Properties at High-Temperature of Nanostructured Fe90-Mg10 Alloys Produced by Mechanical Alloying

2018 ◽  
Vol 54 ◽  
pp. 136-145
Author(s):  
A. El Mohri ◽  
M. Zergoug ◽  
K. Taibi ◽  
M. Azzaz
Keyword(s):  
High Temperature ◽  
Mechanical Alloying ◽  
Milling Time ◽  
High Energy ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
High Energy Ball Mill ◽  
Energy Ball ◽  
The Mean

Nanocrystalline Fe90Mg10 alloy samples were prepared by mechanical alloying process using planetary high energy ball mill. The prepared powders were characterized using differential thermal analysis (DTA), X-ray diffraction technique (XRD) at high temperature, transmission electron microscopy (TEM), and the vibrating sample magnetometer (VSM). Obtained results are discussed according to milling time. XRD at high temperature results also indicated that when the milling time increases, the lattice parameter and the mean level of grain size increase, whereas the microstrains decrease. The result of the observation by the TEM of the Fe-Mg powders prepared in different milling time, coercive fields derived and Saturation magnetization derived from the hysteresis curves in high temperature are discussed as a function of milling time.

Sign in / Sign up

Export Citation Format

Share Document