Local Structure and Magnetic Properties of FeMnAl Nanocrystalline and Amorphous Alloys

2011 ◽  
Vol 277 ◽  
pp. 100-105
Author(s):  
Kontan Tarigan ◽  
D. S. Yang ◽  
S. C. Yu

The structural and the magnetic properties of nanocrystalline and amorphous Fe55Mn10Al35 alloys prepared by the mechanical alloying process are studied as functions of the milling time varying from 1 hr to 48 hrs. Structural analyses based on X-ray diffraction (XRD) and extended X-ray absorption fine structure spectroscopy (EXAFS) reveal that the alloying process took place after 12-hr milling. Nanocrystalline alloys are found until 24-hrs milling, and an amorphous phase afterward. Concerning the magnetic behavior, the data obtained from a vibrating sample magnetometer show that both the magnetization saturation (Ms) and the coercivity (Hc) are dependent strongly on the milling time and the crystallite size. By adjusting the milling time, both appropriate structural transformation and magnetization values are obtained.

2005 ◽  
Vol 877 ◽  
Author(s):  
L. Bessais ◽  
C. Djëga-Mariadassou ◽  
N. X. Phuc

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.


2007 ◽  
Vol 130 ◽  
pp. 171-174 ◽  
Author(s):  
Z. Stokłosa ◽  
G. Badura ◽  
P. Kwapuliński ◽  
Józef Rasek ◽  
G. Haneczok ◽  
...  

The crystallization and optimization of magnetic properties effects in FeXSiB (X=Cu, V, Co, Zr, Nb) amorphous alloys were studied by applying X-ray diffraction methods, high resolution transmission electron microscopy (HRTEM), resistometric and magnetic measurements. The temperatures of the first and the second stage of crystallization, the 1h optimization annealing temperature and the Curie temperature were determined for different amorphous alloys. Activation energies of crystallization process were obtained by applying the Kissinger method. The influence of alloy additions on optimization effect and crystallization processes was carefully examined.


2013 ◽  
Vol 873 ◽  
pp. 217-220
Author(s):  
Min Xu ◽  
Qun Jiao Wang

The paper has described the formation of nanocrystalline Mn80Bi20powders by mechanical alloying and studied the changes of structure and magnetic properties of the powders during the process of ball milling by using X-ray diffraction and saturation magnetization σsmeasurements. The solid solubility of bismuth in manganese increases with milling time and tends to a stable value after 80h milling. The σsof Mn80Bi20increases abruptly with milling time at the early stage and begins to decrease after 15h. At the time of 15h, the σsreaches a maximum, which is about 7Am2/kg. The result shows an interesting information that the antiferromagnetic Mn and the diamagnetic Bi produce ferromagnetic Mn80Bi20in process of mechanical alloying.


2013 ◽  
Vol 203-204 ◽  
pp. 292-295 ◽  
Author(s):  
Krzysztof Ociepka ◽  
Ania Bajorek ◽  
Artur Chrobak ◽  
Grażyna Chełkowska

The magnetic properties and the crystal structure of the ball-milled Tb(Ni0.95Fe0.05)3compound have been studied by using magnetization measurements and X-ray diffraction (XRD). The results were compared with those obtained for the bulk compound prepared by arc-melting technique. The investigated sample is polycrystalline and crystallizes in the rhombohedral PuNi3type of crystal structure (space group R-3m). With the increase of the time milling (i.e. 1 h, 24 h and 48 h) a for-mation of grains less than 1μm and a reduction of magnetocaloric effect have been observed. The analysis of XRD patterns for ball-milled powders shows that after 48h milling time there is still visible a crystalline structure.


2014 ◽  
Vol 70 (a1) ◽  
pp. C1532-C1532
Author(s):  
Hsiao-Tsu Wang ◽  
Mau- Kuen Wu ◽  
Yu-Cheng Shao ◽  
Yu-Fu Wang ◽  
Shang-Hsien Hsieh ◽  
...  

Investigation has been made on atomic, electronic structures and magnetic properties of La0.7Sr0.3MnO3 (LSMO) on Si substrate. The effect of different thickness of LSMO and different morphological [flat and nano-pyramid (NP)] of Si substrate are studied in present work. The result of Mn K-edge extended x-ray absorption fine structure indicates the more disorder of local atomic structure of first shell (Mn-O bound) in the thinner LSMO/Si film. The Mn L3,2-edge x-ray absorption near-edge structure shows the presence of Mn2+ ion on the sample. Furthermore, the Mn L3,2-edge x-ray magnetic circular dichroism reveals that the thinner film (LSMO/Si) has highest magnetic moment, in comparison to that of thick LSMO/Si and LSMO/Si-NP samples. This finding suggests that the appearance Mn2+ may play an important role in magnetic behavior of hetero-junction LSMnO/Si and Si-NP.


2019 ◽  
Author(s):  
Mukul Gupta ◽  
Yogesh Kumar ◽  
Nidhi Pandey ◽  
Akhil Tayal ◽  
Wolfgang Caliebe ◽  
...  

Precise determination of structure of CoN has been achieved combining x-ray diffraction, x-ray absorption spectroscopy measurements and theoretical simulations both at Co and N K-edges and magnetization measurements.<br>


Coatings ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 381 ◽  
Author(s):  
Hasan B. Albargi ◽  
Marzook S. Alshammari ◽  
Kadi Y. Museery ◽  
Steve M. Heald ◽  
Feng-Xian Jiang ◽  
...  

This paper concerns the importance of the preparation of the targets that may be used for pulsed laser deposition of iron-doped indium oxide films. Targets with a fixed concentration of iron are fabricated from indium oxide and iron metal or one of the oxides of iron, FeO, Fe3O4 and Fe2O3. Films from each target were ablated onto sapphire substrates at the same temperature under different oxygen pressures such that the thickness of the films was kept approximately constant. The films were studied using X-ray diffraction, X-ray absorption (both XANES and EXAFS), optical absorption and magnetic circular dichroism. The magnetic properties were measured with a SQUID magnetometer. At the lowest oxygen pressure, there was evidence that some of the iron ions in the films were in the state Fe2+, rather than Fe3+, and there was also a little metallic iron; these properties were accompanied by a substantial magnetisation. As the amount of the oxygen was increased, the number of defect phases and the saturation magnetisation was reduced and the band gap increased. In each case, we found that the amount of the oxygen that had been included in the target from the precursor added to the effect of adding oxygen in the deposition chamber. It was concluded that the amount of oxygen in the target due to the precursor was an important consideration but not a defining factor in the quality of the films.


2012 ◽  
Vol 727-728 ◽  
pp. 430-435
Author(s):  
J.B. Manuel ◽  
M.J. Diniz ◽  
Uílame Umbelino Gomes ◽  
Ariadne de Souza Silva ◽  
J.H. Araújo

Nacrystalline WC-10wt.%Co powders were prepared by high energy milling and liquid phase sintered. The powders with different milling time were characterized by X-ray diffraction and SEM. After sintered the WC-10wt.%Co cemented carbides exhibits ultra fine grain sizes. Coercitive field and Vickers hardness measurements on the consolided samples detected a significant increase and decrease Vickers hardness with the milling time increase in sintered samples.


2005 ◽  
Vol 475-479 ◽  
pp. 3393-3396
Author(s):  
Hui Xu ◽  
Xiao Hua Tan ◽  
Nannan Qi ◽  
Qing Wang ◽  
Yuanda Dong

The glass-forming ability, thermal stability and magnetic properties of the Nd60-xDyxFe30Al10 (x=0, 2, 5) bulk amorphous alloys were investigated by x-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscope (SEM) and the vibrating sample magnetometer (VSM). The results show that the glass forming ability of the Nd60-xDyxFe30Al10 (x=0, 2, 5) alloys decrease with increasing Dy content. The as-cast Nd60-xDyxFe30Al10 (x=0, 2, 5) alloys show hard magnetic behavior at room temperature. With increasing Dy content, the intrinsic coercivity of the alloys increase significantly while the saturation magnetization and remanence of the alloys decrease monotonously. With increasing annealed temperature, the intrinsic coercivity of the Nd55Fe30Al10Dy5 alloy decreased significantly, while the saturation magnetization and remanence decrease monotonously. The Nd55Fe30Al10Dy5 alloy shows soft magnetic behavior after annealed at 773K for 30 min.


2021 ◽  
Vol 9 ◽  
Author(s):  
Yanxin Zhao ◽  
Xiaopeng Sun ◽  
Yanfang Ji ◽  
Hui Kong ◽  
Shumin Chen ◽  
...  

A three-dimensional (3D) Silverton-type polyoxomolybdate (POMo) with the formula of NH4{Mn4[PrMo12O42]}·18H2O (1) was successfully isolated and well characterized by single crystal X-ray diffraction, X-ray powder diffraction pattern, infrared spectrum, thermogravimetric and elemental analyses. The inorganic building block {PrMo12O42} has formed 3D frameworks via the {MnO6} linker. The excitation of compound 1 in solid state at 375 nm displays red emission. Moreover, variable temperature magnetic susceptibility measurements indicate that the magnetic behavior in compound 1 is dominated by antiferromagnetic interactions.


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