排序方式: 共有23条查询结果,搜索用时 31 毫秒
1.
A. Brahimi S. Alleg Z. Yamkane H. Lassri J. J. Suňol E. K. Hlil 《Journal of Superconductivity and Novel Magnetism》2017,30(11):3045-3054
The structure, morphology, and magnetic properties of the mechanically alloyed iron manganese phosphides (Fe1?x Mn x )2P with 0.15 ≤ x ≤ 0.75 (Mn/Fe ratio = 0.17, 0.33, 0.66, and 3) have been studied by means of X-ray diffraction, scanning electron microscopy coupled with energy-dispersive X-ray spectrometry, and BS1 and BS2 magnetometry. The powder form (Fe1?x Mn x )2P compounds exhibit multiphase structures that contain Fe(Mn)-type solid solution and Fe2P-type, Mn2P-type, Fe3P-type, and MnP/FeP-type phosphides. The magnetization versus temperature reveals the existence of multiple magnetic phase transitions. The saturation magnetization, coercivity, and squarness M r/M s ratio values are discussed as a function of both the Mn content and the temperature. From the approach to saturation magnetization studies, several fundamental magnetic parameters were extracted. The local magnetic anisotropy constant K 1 was determined. 相似文献
2.
K. El Aidoudi Z. Yamkane N. Omari M. Khatami H. Lassri L. Bessais E. K. Hlil A. Qachaou 《Journal of Superconductivity and Novel Magnetism》2014,27(8):1911-1916
The magnetotransport properties of Ni81Fe19/W90Ti10 multilayers are investigated. The effect of the thicknesses of magnetic (Ni81Fe19) and nonmagnetic (WTi) layers on the magnetoresistance (MR) is theoretically discussed in the framework of the Johnson–Camley semiclassical approach based on the Boltzmann transport equation. A comparison between the calculated and measured MR ratios is obtained. The observed MR ratio oscillates for WTi layer thickness with an average period of 10 Å. A weak MR(tNiFe) ratio for a fixed tWTi is obtained, and it presents a maximum peak of the MR with a value of 0.8 % located at tNiFe = 50 Å. In addition, electronic and magnetic properties of multilayers are investigated by self-consistent ab initio calculations based on the Korringa–Kohn–Rostocker (KKR) approximation. Spin polarized within the framework of the coherent potential approximation (CPA) is considered for calculations. 相似文献
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Using ab initio calculations on Zn0.975? x Fe0.025Cu x O (x = 0, 0.01, 0.02, 0.05), we study the variations of magnetic moments vs Cu concentration. The electronic structure is calculated by using the Korringa-Kohn-Rostoker (KKR) method combined with coherent potential approximation (CPA). We show that the total magnetic moment and magnetic moment of Fe increase on increasing Cu content. From the density of state (DOS) analysis, we show that Cu-induced impurity bands can assure, by two mechanisms, the enhancement of Fe magnetic moment in Zn0.975? x Fe0.025Cu x O. 相似文献
4.
F. Z. Rachid R. Moubah R. El Ouatib S. Derkaoui H. Lassri 《Journal of Superconductivity and Novel Magnetism》2018,31(7):2073-2077
Amorphous Co75Er17B8 ribbons were prepared by the melt spinning technique, and their magnetic properties were studied. Mean field theory was used to describe the temperature dependence of magnetization. High-field magnetization studies performed in magnetic fields up to 15 T have revealed a magnetic behavior typical of a non-collinear magnetic structure of Er and Co sublattices. The simulated magnetization curves show the existence of two critical fields at H cri1 =?9.5 T and H cri2 =?94.2 T, corresponding to collinear ferrimagnet, and collinear field-forced ferromagnetic behaviors. The high value of H cri2 highlights the strong antiferromagnetic interaction between Er and Co sublattices. From the non-collinear regime, the inter-subnetwork molecular field coefficients of the ferrimagnetic alloy were accurately evaluated. In addition, it is shown that the region of canted moments can be satisfactorily described by a phase diagram in the H-T plane. 相似文献
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K. Chafai H. Lassri M. Abid E. K. Hlil 《Journal of Superconductivity and Novel Magnetism》2012,25(1):117-123
Magnetic properties of Fe/Ag multilayer films are investigated and examined versus Fe layer thickness t
Fe. As a result, spontaneous magnetization M(T) temperature dependence has been revealed to be well described by a T
3/2 law in all multilayer films (7 ?≤t
Fe≤60 ?). Spin-wave theory based on anisotropic ferromagnetic system has been also used to explain magnetization temperature
dependence. For Fe layer thickness, approximate values for J
0 bulk exchange interaction and J
s
surface exchange interaction have been estimated. First principle calculations based on density functional theory (DFT) and
Korringa–Kohn–Rostoker (KKR)—coherent potential approximation (CPA) method—combined with Local Spin Density Approximation
(LSDA), are performed as well. Magnetic moment, in fcc Ag1−x
Fe
x
and bcc Fe1−x
Ag
x
systems, versus x is presented and discussed in terms of Fe content on magnetic coupling. Reasonable agreement between experimental data and
theoretical calculations is highlighted. 相似文献
7.
A. El Amiri M. Abid H. Lassri E. K. Hlil 《Journal of Superconductivity and Novel Magnetism》2012,25(7):2529-2532
By ab-initio calculations on Zn0.95?x Co0.05Cu x O, we study the variations of magnetic moments versus Cu concentration. The electronic structure is calculated by using the Korringa?CKohn?CRostoker (KKR) method combined with coherent potential approximation (CPA). We show that the total magnetic moment and magnetic moment of Co increase with increasing Cu content. From a density of state (DOS) analysis, we propose an explanation of the enhancement of the Co magnetic moment versus Cu concentration. 相似文献
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