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.

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.

Magnetic Properties of Nanocrystalline Fe50Co50 Powders

2003 ◽  
Vol 788 ◽  
Author(s):  
Shashishekar Basavaraju ◽  
Ian Baker
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Magnetic Force ◽  
Milling Time ◽  
Magnetic Behavior ◽  
High Energy ◽  
Soft Magnetic ◽  
Scanning Calorimetry ◽  
High Energy Ball Mill ◽  
Energy Ball

ABSTRACTNanocrystalline stoichiometric FeCo powders were prepared by mechanically alloying elemental Fe and Co powders using a high-energy ball mill. The microstructural evolution was studied as a function of milling time and subsequent annealing using X-ray diffractometry and differential scanning calorimetry. The magnetic behavior of the specimens was characterized using a vibrating sample magnetometer and a magnetic force microscope. A reduction in grain size coupled with an increase in coercivity was observed as function of milling time. The smallest grain size of 4 nm, which exhibited a coercivity of 122 Oe and magnetization of 2 T at room temperature, was obtained after 240 h of milling. The reduction in grain size during milling was not accompanied by enhanced soft magnetic properties.

NITROGENATION AND SUBSEQUENT SURFACTANT-ASSISTED HIGH ENERGY BALL MILLING OF Sm2Fe17 MELT-SPUN POWDERS

2013 ◽  
Vol 06 (04) ◽  
pp. 1350038 ◽  
Author(s):  
LIXIN ZHAO ◽  
LIYUN ZHENG ◽  
GEORGE C. HADJIPANAYIS
Keyword(s):  
Magnetic Properties ◽  
Ball Milling ◽  
High Energy ◽  
Milling Process ◽  
High Energy Ball Milling ◽  
Soft Phase ◽  
X Ray ◽  
Melt Spun ◽  
Energy Ball ◽  
Surfactant Assisted

Sm 2 Fe 17 melt-spun powders were subjected to the nitriding process and followed by surfactant-assisted high-energy ball milling (HEBM). The microstructures, morphology and magnetic properties were also investigated by X-ray diffractometer, scanning electron microscope and vibrating sample magnetometer. The results showed that the coercivities of the nitrided Sm 2 Fe 17 powders were 1.64 kOe and 3.65 kOe when the nitriding temperatures were 350°C and 450°C, respectively. When the nitriding temperature was 350°C, there was a wasp-shaped hysteresis loop, due to the soft phase of iron, formed during the nitrogenation process. The subsequent surfactant-assisted HEBM can further improve the magnetic properties of the nitrided Sm 2 Fe 17 powders and a 3 h milling process increased the coercivity of the sample nitrided at 450°C reached a high value of 6.97 kOe.

Effect of High Energy Ball Milling Washing Process on Properties of Nd2Fe14B Particles Obtained by Reduction-Diffusion

2019 ◽  
Vol 822 ◽  
pp. 244-251
Author(s):  
Vitalii Galkin ◽  
Kamran Haider ◽  
Jong Bin Ahn ◽  
Dong Soo Kim
Keyword(s):  
Magnetic Properties ◽  
Ball Milling ◽  
Magnetic Particles ◽  
Neodymium Oxide ◽  
High Energy ◽  
Milling Process ◽  
Milling Parameters ◽  
Washing Process ◽  
Planetary Ball Milling ◽  
Energy Ball

Nd2Fe14B particles were obtained from mixture of neodymium oxide, iron oxide, boric acid and CaH2 by reduction-diffusion process. Two different washing processes were used for the separation of magnetic particles from Ca and CaO matrix: usual washing with water and planetary ball milling process in ethanol media. Nd2Fe14BHx hydrogenated state was formed after usual washing with water. Ethanol planetary ball milling washing procedure prevented the formation of Nd2Fe14B hydrides during washing. Variation of milling parameters allowed producing particles with different morphology such as spherical or flakes after planetary ball milling washing process. Influence of milling parameters on magnetic properties of Nd2Fe14B powder was investigated.

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.

Investigations on the Magnetic Properties of High-Coercivity Nd40Fe30Co15Al10B5 Bulk Amorphous Alloys

2005 ◽  
Vol 877 ◽  
Author(s):  
L. Bessais ◽  
C. Djëga-Mariadassou ◽  
N. X. Phuc
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Magnetic Behavior ◽  
High Energy ◽  
High Coercivity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Leading Role ◽  
Remanence Ratio ◽  
Transmission Electron

AbstractNd40Fe30Co15Al10B5 bulk amorphous prepared by high energy milling shows a coercivity of 8.1 kOe with a Curie temperature of 645 K. The controlled nanocrystallization enhances the coercivity to 20 kOe and the remanence ratio is equal to 0.59. The coexistence of two crystalline magnetic phases, ferromagnetic Nd2(Fe,Co,Al)14B and antiferromagnetic Nd6(Fe,Co,Al)14 are revealed by x-ray diffraction, high-resolution transmission electron microscopy, magnetization measurements, and Mössbauer spectrometry. The grain size for optimal magnetic properties is around 30 nm. The nucleation process may play a leading role in the high magnetic behavior.

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.

scholarly journals Magnetic properties and crystal structure of elemental cobalt powder modified by high-energy ball milling

2019 ◽  
Vol 8 (5) ◽  
pp. 4995-5003 ◽  
Author(s):  
J.A. Betancourt-Cantera ◽  
F. Sánchez-De Jesús ◽  
A.M. Bolarín-Miró ◽  
G. Torres-Villaseñor ◽  
L.G. Betancourt-Cantera
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Ball Milling ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Cobalt Powder ◽  
Energy Ball

scholarly journals Magnetic properties of iron nitride-alumina nanocomposite materials prepared by high-energy ball milling

2003 ◽  
Vol 24 (1-3) ◽  
pp. 93-96 ◽  
Author(s):  
S. R. Mishra ◽  
G. J. Long ◽  
F. Grandjean ◽  
R. P. Hermann ◽  
S. Roy ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Ball Milling ◽  
High Energy ◽  
Nanocomposite Materials ◽  
High Energy Ball Milling ◽  
Iron Nitride ◽  
Energy Ball

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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