Structure, magnetic properties and Mössbauer spectra of La0.67Sr0.33FexMn1 − xO3 manganites oxide prepared by mechanical ball milling method

2012 ◽  
Vol 211 (1-3) ◽  
pp. 153-164 ◽  
Author(s):  
Wajdi Chérif ◽  
Mohamed Ellouze ◽  
Abdel-Fatah Lehlooh ◽  
Sami H. Mahmood ◽  
Foued Elhalouani
2013 ◽  
Vol 49 (9) ◽  
pp. 939-942
Author(s):  
V. V. Parfenov ◽  
A. V. Pyataev ◽  
I. I. Nig’matullina ◽  
Sh. Z. Ibragimov

2009 ◽  
Vol 152-153 ◽  
pp. 49-53
Author(s):  
V.V. Serikov ◽  
N.M. Kleinerman ◽  
N.V. Volkova ◽  
N.I. Kourov

The Mössbauer spectra of PdMnxFe1-x alloys obtained at 80 K and at 300 K were studied in the 0.2 < x < 0.8 concentration range, in which there realizes a microinhomogeneous multiphase medium formed by isostructure phases of the constituent compositions: ferromagnetic PdFe (ТС=730 К) alloy undergoing atomic ordering and antiferromagnetic PdMn (TN=815 К) intermetallic compound. Magnetic properties studies evidence the presence of a third presumably noncollinear phase with its own ordering temperature lying below the Curie temperature of the ferromagnetic phase in the 0.2 < x < 0.8 concentration range. The Mössbauer spectra at 300 K exhibit a doublet for antiferromagnetic alloys (x > 0.8) and a sextet at Hhf ~350 kOe for ferromagnetic alloys (x < 0.2). In the intermediate concentration range several peaks 0 < Hhf < 350 kOe have been observed in the P(Hhf) curves, which result from microinhomogeneous multiphase state.


Clay Minerals ◽  
1988 ◽  
Vol 23 (4) ◽  
pp. 367-377 ◽  
Author(s):  
D. H. Doff ◽  
N. H. J. Gangas ◽  
J. E. M. Allan ◽  
J. M. D. Coey

AbstractPillared smectites in which the pillars consist of iron oxide are expected to have interesting and unusual magnetic properties. Several possible routes by which such materials might be made have been investigated, namely intercalation of hydroxy-Fe(III) polycations, mixed hydroxy-Fe(III)/Al polycations, phenanthroline-Fe(II) cations, and trinuclear Fe(III) acetato cations into Na-montmorillonite. Only the last of these yielded a pillared clay (PILC) on calcination. The products have been characterized using X-ray powder diffraction and 57Fe Mössbauer spectroscopy. The precursor Fe-PILC has a d-spacing of 21 Å and expands to 23 Å on solvation with glycol. The calcined Fe-PILC has a d-spacing of 19 Å (gallery height 9·4 Å) and does not expand with glycol, confirming cross-linking of the layers. From Mössbauer spectra at 4·2 K it is estimated that there are of the order of some hundred Fe atoms per pillar.


2020 ◽  
Vol 858 ◽  
pp. 53-58
Author(s):  
Ai Xia Chen ◽  
Chao Yang ◽  
Rui Hua Wang ◽  
Fang Wang ◽  
Ming Han Xu ◽  
...  

In this paper, the effect of raw materaisl on the properties of coated Al2O3/Al cermet materials were investigated, the raw materials were prepared via different methods, which provide a reference for obtaining higher performance cermet materials. Through mixing, molding, sintering, sample preparation, scanning electron microscopic observation, energy spectrometer observation and analysis, the following conclusions can be drawn, the density of the cermet material prepared by the mechanical ball milling method (83.5%) is higher than that of the cermet material prepared by the chemical precipitation method (92.8%). It is nearly 10% lower. The alumina particles prepared by the ball milling method are agglomerated, and a large amount of agglomeration occurs in the aluminum, and the composition is very uneven. For materials prepared by the precipitation method, the aluminum oxide is uniformly distributed in the aluminum. The ball-milling powder is used to prepare materials, most of the alumina is in the form of particles, and in the precipitation method. In the powder preparation sample, the thin layer of alumina which forms the same eggshell envelops the aluminum, and the aluminum has a certain liquid phase change. the surface hardness (824HV) of the cermet material prepared by the mechanical ball milling method is lower than the surface hardness (1005HV) of the cermet material prepared by the chemical precipitation method.


Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 24 ◽  
Author(s):  
Munirah Almessiere ◽  
Yassine Slimani ◽  
Hakan Güngüneş ◽  
Abdulhadi Baykal ◽  
S.V. Trukhanov ◽  
...  

Manganese (Mn)- and yttrium (Y)-substituted Sr-nanohexaferrites (MYSNHFs) of composition Sr1−xMnxFe12−xYxO19 (with 0.0 ≤ x ≤ 0.5) were prepared by citrate sol-gel autocombustion method. As-prepared MYSNHFs were characterized via diverse analytical techniques to determine the influence of Mn and Y cosubstitution on their microstructures and magnetic properties. 57Fe Mössbauer spectra of the MYSNHFs were used to evaluate the variation in the line width, isomer shift, quadrupole splitting, and hyperfine magnetic field values. It was shown that the dopant ions could preferentially occupy the 12k, 4f2, and 2b sites. Furthermore, the observed shift in the blocking temperatures of the studied MYSNHFs towards lower values with rising Mn2+ and Y3+ contents was attributed to the overall particles size reduction. Meanwhile, the AC susceptibility of the proposed MYSNHFs revealed that the magnetic interactions were weakened with the increase in dopant contents which was ascribed to the replacement of both Sr2+ and Fe3+ ions by the Mn2+ and Y3+ dopants.


1994 ◽  
Vol 94 (1) ◽  
pp. 2067-2073 ◽  
Author(s):  
Qinian Qi ◽  
K. O'Donnell ◽  
E. Touchais ◽  
J. M. D. Coey

1972 ◽  
Vol 50 (19) ◽  
pp. 2313-2326 ◽  
Author(s):  
M. R. Spender ◽  
J. M. D. Coey ◽  
A. H. Morrish

The magnetic properties of a number of samples of synthetic Fe3S4 have been studied using both static magnetization measurements and Mössbauer effect spectrometry. The distinction is made between the intrinsic properties of bulk Fe3S4 and observations resulting from superparamagnetic behavior and nonstoichiometry. Mössbauer spectra in applied fields show that the bulk material has a simple Néel ferrimagnetic spin arrangement. The magnetic moment at 4.2 °K is 2.2 ± 0.3 μB per formula unit and the ordering temperature is 606 ± 2 °K. Conductivity measurements indicate semimetallic behavior and two alternative band schemes are proposed to account for this feature and explain the magnetic moment.


RSC Advances ◽  
2018 ◽  
Vol 8 (66) ◽  
pp. 38047-38055 ◽  
Author(s):  
Lei Xiao ◽  
Yan Zhang ◽  
Xiaohong Wang ◽  
Gazi Hao ◽  
Jie Liu ◽  
...  

To research the influence of aluminum (Al) on the decomposition of 1,3,5-trimethylene trinitramine (RDX), superfine RDX/Al composite with a mass ratio of 70/30 was prepared by mechanical ball milling.


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