The Effects of Ternary Elemental Additions on the Structure and Magnetic Properties of Nanocrystalline Feco Powders

2002 ◽  
Vol 753 ◽  
Author(s):  
I. Baker ◽  
R. G. Quiller ◽  
M. Robson ◽  
D. Wu

ABSTRACTPowders of near-equiatomic Fe and Co were mechanically milled with additions of Zr, C, Ni, Cu and/or B for 60 hr using stainless steel balls in a Svegari attritor operated at 1300 r.p.m. under argon. The milled powders were examined before and after annealing at 600 °C. The morphologies and sizes of the powders were examined using a scanning electron microscope. The grain sizes were characterized from the widths of X-ray diffraction peaks obtained using a computer-controlled x-ray diffractometer and the lattice parameters were determined. The resulting magnetic properties were measured using a vibrating sample magnetometer.

2017 ◽  
Vol 48 ◽  
pp. 171-176
Author(s):  
Rahim Sabbaghizadeh ◽  
Roslinda Shamsudin ◽  
Samikanu Kanagesan ◽  
Ghazaleh Bahmanrokh

In this study, Nanocrystalline Nd8Pr2Fe79-xCo5B6Alx (x= 0, 1, 2, 3) magnets were prepared by mechanical alloying method and respective heat treatment in a constant time and temperature. Afterward, the effects of the Al addition on the microstructure and magnetic properties of Nd-Fe-Co-B alloy were studied. The changes in the nanostructure and magnetic properties were examined by X-Ray diffraction (XRD), combined with Field Emission Scanning electron microscopy (FeSEM) and vibrating sample magnetometer (VSM). Addition of Al was found to be effective for improving the coercivity parameter and the hysteresis squareness in Nd–Fe–Co–B magnets without decreasing much the remanent magnetization.


2013 ◽  
Vol 423-426 ◽  
pp. 885-889 ◽  
Author(s):  
Yi Gao Yuan ◽  
Jian Jun Ding ◽  
Yan Kun Wang ◽  
Wei Quan Sun

The carburizing heat treatments of ultrafine-grained WC-Co composites with sub-stoichiometric carbon content were carried out, and the microstructures of ultrafine-grained WC-Co carbides before and after treated were characterized by means of scanning electron microscopy and X-ray diffraction. The results show that the functionally gradient ultrafine-grained WC-Co hardmetals with a Co depleted surface and not comprising the η-phase can be fabricated by carburizing heat treatment. After heat treatment, WC grain sizes in materials are still at the ultrafine grade.


2012 ◽  
Vol 11 (05) ◽  
pp. 1250036 ◽  
Author(s):  
WEIGAO WANG ◽  
FAGEN LI ◽  
FAN ZHAO ◽  
JUN WANG ◽  
GUOMENG ZHAO

Fe7S8 nanorods have been successfully synthesized using a chemical evaporation method. X-ray diffraction pattern showed that the as-prepared products were Fe7S8 with no impurity phase. The results of scanning electron microscopy indicated that the samples synthesized at 750°C and 900°C were rod and sheet-like, respectively. The magnetic properties of the iron sulfide nanorods were measured over a wide temperature range (4 K–750 K) using a quantum design vibrating sample magnetometer. It was found that the nanorods were ferromagnetic with the Curie temperature of about 581 K. The Mössbauer spectra showed that the iron sulfide nanorods consisted of hexagonal pyrrhotites, whose spectra were asymmetrical according to correlation between the isomer shift and the hyperfine field.


2021 ◽  
Vol 66 (1) ◽  
pp. 57-64
Author(s):  
Hang Pham Vu Bich ◽  
Yen Nguyen Hai ◽  
Mai Phung Thi Thanh ◽  
Dung Dang Duc ◽  
Hung Nguyen Manh ◽  
...  

In this study, we present the process of synthesis FexNi1-xMn2O4 (x = 0; 0.1; 0.3; 0.5; 0.7; 0.9; 1) by method sol-gel. Scanning electron microscope results shows that the particle size is about 50 nm. The X-ray diffraction diagram shows that the samples are single phase, changing structure clearly as the x ratio increases from 0 to 1. The lattice constant, the bond length also changes with x-value as shown on the Raman scattering spectrum. The results of the vibrating sample magnetometer show that the magnetism of the material FexNi1-xMn2O4 changes with the value of x and reaches a maximum in the range x from 0.5 to 0.7.


2007 ◽  
Vol 43 (2) ◽  
pp. 141-150 ◽  
Author(s):  
G.P. Vassilev ◽  
K.I. Lilova ◽  
J.C. Gachon

Phase equilibria were studied in the system Ni-Sn-Bi. Special attention has been paid to the identification of the recently found ternary phase. For this purpose samples were synthesized using intimately mixed powders. After annealing and quenching, all alloys were analyzed by scanning electron microscope and by X-ray diffraction. The results give evidences about the existence of a ternary compound with approximate formula Ni6Sn2Bi to Ni7Sn2Bi. Overlapping of some neighboring diffraction peaks of this phase with NiBi and Ni3Sn_LT is the reason for the difficulties related to the X-ray diffraction identification of the ternary phase.


2012 ◽  
Vol 268-270 ◽  
pp. 241-244
Author(s):  
Bin Bin Zhao ◽  
Xue Gang Luo ◽  
Xiao Yan Lin ◽  
Hong Ping Zhang

This paper studied the property changes of environmental degradation mulching film and polyethylene mulching film in water environment. The XRD (X-ray diffraction) cures showed that the diffraction angles of environmental degradation mulching film were not changed but intensities and area of diffraction peaks increased after immersion for 60 days; while the diffraction angles and area of diffraction peaks of polyethylene mulching film were same before and after immersion. Cracks and holes appeared in surface of environmental degradation mulching film, but it was still smooth and uniform for the polyethylene mulching film after immersion.


2010 ◽  
Vol 24 (30) ◽  
pp. 5973-5985
Author(s):  
M. GUNES ◽  
H. GENCER ◽  
T. IZGI ◽  
V. S. KOLAT ◽  
S. ATALAY

NiFe 2 O 4 nanoparticles were successfully prepared by a hydrothermal process, and the effect of temperature on them was studied. The particles were annealed at various temperatures ranging from 413 to 1473 K. Studies were carried out using powder X-ray diffraction, scanning electron microscopy, infrared spectroscopy, differential thermal analysis, thermogravimetric analysis and a vibrating sample magnetometer. The annealing temperature had a significant effect on the magnetic and structural parameters, such as the crystallite size, lattice parameter, magnetization and coercivity.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4962
Author(s):  
Pawel Pietrusiewicz ◽  
Marcin Nabiałek ◽  
Bartłomiej Jeż

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.


2015 ◽  
Vol 1101 ◽  
pp. 286-289 ◽  
Author(s):  
Maya Rahmayanti ◽  
Sri Juari Santosa ◽  
Sutarno

Gallic acid-modified magnetites were synthesized by one and two-step reactions via the newly developed sonochemical co-precipitation method. The two-step reaction included the formation of magnetite powder and mixing the magnetite powder with gallic acid solution, while the one-step reaction did not go through the formation magnetite powder. The obtained gallic acid-modified magnetites were characterized by the Fourier Transform Infrared (FTIR) spectroscopy, the X-Ray Diffraction (XRD) and the Scanning Electron Microscopy (SEM). More over, the magnetic properties were studied by using a Vibrating Sample Magnetometer (VSM). The characterization results showed that there were differences in crystalinity, surface morphology and magnetic properties of products that were formed by one and two-step reactions.


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