scholarly journals Влияние температуры продолжительного отжига на структуру и магнитные свойства нанокристаллического сплава FeSiNbCuB

2021 ◽  
Vol 63 (7) ◽  
pp. 834
Author(s):  
Н.В. Ершов ◽  
Ю.П. Черненков ◽  
В.А. Лукшина ◽  
О.П. Смирнов ◽  
Д.А. Шишкин

A dependence of the soft magnetic properties of the Fe73.5Si13.5Nb3Cu1B9 alloy on the temperature of annealing (Tan) carried out in air for 2 hours at temperatures from 520 to 620°C was investigated. It was shown that with Tan increasing, the magnetic hysteresis loop broadens significantly and becomes more inclined, and the Curie temperature of the amorphous matrix surrounding the α-FeSi nanocrystals decreases. The atomic structure and phase composition of the alloy samples were investigated by X-ray diffraction in transmission geometry. After annealing at temperatures of up to 580°C, nanocrystals contain predominantly D03 phase (Fe3Si stoichiometry) and have average size of about 7 nm. Their relative fraction in the alloy increases as the temperature increases due to the additional diffusion of iron from the matrix into the nanocrystals. After annealing at Tan ≥ 600°C, the average size of the nanocrystals increases, and reflections of iron boride crystals appear in the diffractograms. The deterioration of the soft magnetic properties of the Fe73.5Si13.5Nb3Cu1B9 nanocrystalline alloy, when the annealing temperature rises from 520 to 580°C, is explained by a decrease in the silicon concentration in Fe-Si nanocrystals, which leads to a growth of the constant of the magnetocrystalline anisotropy.

2018 ◽  
Vol 29 (22) ◽  
pp. 19517-19523 ◽  
Author(s):  
Huiyun Xiao ◽  
Anding Wang ◽  
Chengliang Zhao ◽  
Aina He ◽  
Guoyang Zhang ◽  
...  

2021 ◽  
Vol 19 (10) ◽  
pp. 20-28
Author(s):  
Dhifaf Hussain Hassan ◽  
Sabah Jalal Fathi

The compound was prepared by sol-gel method for spontaneous combustion with certain weight ratios (x=0.0,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9), the samples were calcined at a temperature (900oC) for a period of two hours(2h), then studied its structural and magnetic properties.one of the most prominent results that we obtained from the X-ray diffraction technique (XRD) is that compound has several phases. Where the sample (NiFe2O4) appeared to be polycrystalline and the dominant phase in it is the cubic phase, while the other phase is (Hematite)(Fe2O3) A crystal structure rhomboid (Rhombohedral), in addition to these two phases, the phase with the existing quaternary structure appeared (Sr2Fe2O5) its called (Orthorhombic). The results of the magnetic properties that were obtained through the (VSM) device, and one of the most important of these properties is the magnetic hysteresis loop by analyzing the magnetic hysteresis loop at (x=0.3), where the least area of the hysteresis loop or the least width of the hysteresis loop One of the most important parameters of the magnetic properties is the saturation magnetism (μS) and its value ranges from (19.76-3.86) (emu/gr), the highest value was at (X=0.3) and its value is (19.76emu/gr) and in general its value decreases with increasing concentration of strontium. The residual magnetism (Mr) ranges between (7.45-1.58) (emu/gr), where it reached its highest value at (x=0.3) and its value is (7.45emu/gr), and generally its value decreases with increasing concentration of strontium. In addition to that, there is another parameter which is coercion or Magnetic coercivity (Hc) ranges in value (1751.104-209.26) (Oe), reaching its lowest value at (x=0.3), and then increases with increasing strontium concentration until it reaches its highest value at (x=0.9), where it reached its value is (1751.104Oe). The square rate represented by the symbol (μi) has high values. This means that there is a mutual coupling between the soft and hard magnetic phases, which was the highest value at (x=0.3) and its value is (4.93).


2013 ◽  
Vol 320 ◽  
pp. 83-87 ◽  
Author(s):  
Yue Gu ◽  
Yue Sheng Chao

The stability and the soft magnetic properties of amorphous Fe52Co34Hf7B6Cu1 alloys have been investigated in this paper. Amorphous Fe52Co34Hf7B6Cu1 alloys ribbons are prepared by single-roller-quenching method. The differential thermal analysis (DTA), X-ray diffraction (XRD), Mössbauer Spectroscopy, transmission electron microscope (TEM) and vibrating sample magnetometer (VSM) were used for characterizing microstructures, soft magnetic properties, and evaluating the influence of adding manners of B on the stability of as-quenched specimens. The XRD curve shows a wide dispersion of peak, the TEM diffraction ring was dispersed cyclic, the pattern of the matrix was homogeneous, and the Mössbauer spectrum of as-quenched alloy presents a typical broadened and overlapped sextet, which confirms the as-quenched alloy in fully amorphous state. The DTA results showed the activation energy of Fe52Co34Hf7B6Cu1 alloy is 299.7KJ/mol. When pure B is replaced by FeB in preparing amorphous Fe52Co34Hf7B6Cu1 alloys, the activation energy reduced to 293.3 KJ/mol,and the soft magnetic property is decline according VSM results.


2007 ◽  
Vol 316 (2) ◽  
pp. e886-e889 ◽  
Author(s):  
A.K. Panda ◽  
O. Mohanta ◽  
A. Mitra ◽  
D.C. Jiles ◽  
C.C.H. Lo ◽  
...  

2008 ◽  
Vol 570 ◽  
pp. 150-154 ◽  
Author(s):  
F. Saporiti ◽  
A.H. Kasama ◽  
B. Arcondo ◽  
Walter José Botta Filho ◽  
Claudio Shyinti Kiminami ◽  
...  

Fe-Si alloys have excellent soft magnetic properties, specially around 12 at% Si. However, its industrial application is limited because of the lack of ductility, which causes cracking during rolling operations for the fabrication of thin sheets. The reason of the brittleness of the high silicon alloys is a disorder/order reaction at low temperatures. The aim of this work is to analyze the effect of the addition of Aluminum on the crystalline structure of Fe-Si alloys. Samples with a chemical composition of Fe88Si12 and Fe87Si12Al1 (at%) were prepared by Spray Forming. The structure was studied by means of X-ray diffraction and Mössbauer Spectroscopy. The presence of the DO3 and α- Fe phases were observed


2012 ◽  
Vol 482-484 ◽  
pp. 2365-2370 ◽  
Author(s):  
Qian Li Ma ◽  
Yong Bao ◽  
Guo Rui Zhang ◽  
Li Meng Yu ◽  
Ling Fei Ji ◽  
...  

The paper presents a laser irradiation method for rapidly fabricating Fe-based nanocrystalline alloys using Yb-doped fiber laser with a wavelength of 1070nm by overlapping irradiation of the heated areas. The samples are annular cores rolled with 20μm-thick and 3.2mm-wide belts of amorphous alloy Fe73.5Cu1Nb3Si13.5B9, which have internal diameter of 14 mm and external diameter of 20 mm. Every side of the samples is irradiated for 15 min by fiber laser. X-ray diffraction and transmission electron microscopy (TEM) are used for microstructure analysis and observation. The samples irradiated by a defocus beam with a diameter of 7.1mm through a lens have better soft magnetic properties than directly by an original collimating beam with a diameter of 6.7mm. The dimension of homogeneous ultrafine grains is about 10nm with a bcc α-Fe (Si), which is the foundation of the excellent soft magnetic property. Uniform laser irradiation and the appropriate laser power are necessary for optimum microstructure and soft magnetic properties.


2003 ◽  
Vol 18 (12) ◽  
pp. 2799-2806 ◽  
Author(s):  
Akihisa Inoue ◽  
Baolong Shen

Ribbon and bulk nanocrystalline body-centered-cubic (bcc) (Fe,Co) alloys exhibiting good soft magnetic properties were synthesized in Fe71.5-xCoxB13.5Si10Nb4Cu1 system by the simple production processes of melt-spinning or casting and annealing. The glass-type alloys were formed in the Co content range below 30 at.%. These glassy alloys crystallized through two exothermic reactions. The first stage was due to the precipitation of nanoscale bcc-(Fe,Co) phase with a grain size of about 10 nm, and the second stage resulted from the decomposition of the remaining amorphous phase to α–(Fe,Co), (Fe,Co)2B, (Fe,Co)23B6, (Fe,Co)3Si, and (Fe,Co)2Nb phases. The glass transition temperature increased from 820 to 827 K with increasing Co content from 5 to 20 at.%, while the supercooled liquid region decreased slightly from 37 to 30 K because of the nearly constant crystallization temperature. By choosing the 10 at.% Co-containing alloy, we produced cylindrical glassy alloy rods 1.0 and 1.5 mm in diameter by copper mold casting. The subsequent annealing for 300 s at 883 K corresponding to the temperature just above the first exothermic peak caused the formation of nanoscale bcc-(Fe,Co) structure. The bcc-(Fe,Co) alloy rods exhibited good soft magnetic properties of 1.26 T for saturation magnetization and 5.0 A/m for coercive force, which were comparable to those for the corresponding bcc-(Fe,Co) alloy ribbon. The nanocrystalline alloy in a bulk form is encouraging for future use as a new type of soft magnetic material that requires three-dimensional shapes.


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