scholarly journals The effect of shape toward characteristics of cerium-iron-boron thin layer

2021 ◽  
Vol 926 (1) ◽  
pp. 012040
Author(s):  
A Indriawati ◽  
R Sari ◽  
Sulanjari
Keyword(s):  
Thin Layer ◽  
Magnetic Moment ◽  
Magnetic Moments ◽  
Anisotropy Energy ◽  
Micromagnetic Simulations ◽  
Rectangular Shape ◽  
Energy Value ◽  
Spintronic Devices ◽  
Magnetic Devices ◽  
Circular Shape

Abstract The development of spintronic devices in the magnetic memories industry has attracted researchers over decades. Therefore, researchers are trying to obtain materials which compatible to improve device performance. These materials are made in the form of thin layer. Cerium-iron-boron (Ce-Fe-B) alloy is one of potential materials to be applied for magnetic devices. In this study, the nucleation changes in the Ce-Fe-B thin layer were analyzed using circular and rectangular shapes. This phenomenon was observed through micromagnetic simulations. The magnetic moment stability of Ce-Fe-B was analyzed based on the response of the magnetic moment towards the presence of an external magnetic field. The magnitude of applied external magnetic applied is 0.4 Tesla in x-axis direction. Changes in the arrangement of magnetic moments due to external magnetic fields produce magnetization and anisotropy energy value which describing the characteristics of the Ce-FeB thin layer. Magnetization value of Ce-Fe-B thin film in circular shape was greather than rectangular shape. These value was 0.98 for circular shape and 0.93 for rectangular shape. On the other hand, anisotropy energy value on magnetic external apllied 400 mT, circular shape anisotropy energy’s value of Ce-Fe-B was 4.85×10-18 J, and 6.71×10-18 J for rectangular shape.

Magnetic properties of small ruthenium clusters in fullerene cage — A DFT study

2014 ◽  
Vol 28 (27) ◽  
pp. 1450184 ◽  
Author(s):  
Sunita Srivastava ◽  
Akshu Pahuja
Keyword(s):  
Magnetic Moment ◽  
Density Functional ◽  
Magnetic Moments ◽  
Fullerene Cage ◽  
Gap Formation ◽  
Functional Theory ◽  
Magnetic Devices ◽  
Ruthenium Atom ◽  
Small Clusters ◽  
Homo Lumo

Encapsulation of small clusters in fullerene cages provides a stable environment for their application in nanoscale functional devices. In this paper, first principles study of Ruthenium as an endohedral dopant in buckminsterfullerene has been carried out using density functional theory. Ruthenium atom has three stable dopant sites inside C 60, with three possible values of magnetic moment (4, 2 and 0 μB). The doping position of Ru atom can be seen to have an effect on HOMO–LUMO gap, formation energy, binding energy and magnetic moment of the fullerene cage. The interaction between Ru and C atoms in different conformations can be explained in terms of Mulliken analysis and density of states analysis. It is also possible to encapsulate more than one Ru atoms in the C 60 cage ( Ru n@ C 60, n = 2–6); encapsulation up to six atoms has been analyzed, after which the process is energetically unfavorable. The geometry of the lowest energy structures, compared to the isolated Ru n clusters, is found to change as a result of encapsulation (e.g., in Ru 3@ C 60 and Ru 5@ C 60). A reduction in magnetic moment of Ru clusters inside fullerene cage as compared to isolated clusters also occurs due to hybridization and confinement effects. The varied magnetic moments of Ru -encapsulated C 60 molecules reveal its applications in molecular magnetic devices and quantum peapods.

Theoretical study of the magnetic moments and anisotropy energy of CoRh nanoparticles

2009 ◽  
Vol 52 (1-3) ◽  
pp. 171-174 ◽  
Author(s):  
M. Muñoz-Navia ◽  
J. Dorantes-Dávila ◽  
M. Respaud ◽  
G. M. Pastor
Keyword(s):  
Theoretical Study ◽  
Magnetic Moments ◽  
Anisotropy Energy

The influence of rectangular shape holes on energy intensity of grinding grain

2021 ◽  
pp. 18-23
Author(s):  
A. V Cherepkov ◽  
I. V. Konoshin
Keyword(s):  
Gastric Juice ◽  
Specific Energy ◽  
Energy Intensity ◽  
Conversion Coefficient ◽  
Grinding Process ◽  
Theoretical Evaluation ◽  
Surface Theory ◽  
Rectangular Shape ◽  
German Scientist ◽  
Circular Shape

Grain before feeding to animals exposed to grinding with the purpose of increasing its digestibility. As a result of this increases the area of interaction of the feed with the gastric juice and decreases the conversion coefficient. Surface theory formulated by German scientist Rittinger, suggests that the work of AR required for the grinding process is directly proportional to newly formed surface. The purpose of this paper is a theoretical evaluation of the intensity of grinding with the use of sieves with rectangular and circular shape holes. When getting groats with the same grinding module by the use of sieves with holes of rectangular shape, one should expect the decrease of specific energy intensity. By reducing the content of dust-like fractions and reduce the total surface feed should be expected to reduce the energy intensity of pneumo transportation.

scholarly journals Spin Gapless Semiconductor–Nonmagnetic Semiconductor Transitions in Fe-Doped Ti2CoSi: First-Principle Calculations

2018 ◽  
Vol 8 (11) ◽  
pp. 2200 ◽  
Author(s):  
Yu Feng ◽  
Zhou Cui ◽  
Ming-sheng Wei ◽  
Bo Wu ◽  
Sikander Azam
Keyword(s):  
Magnetic Moment ◽  
Electronic Structures ◽  
Magnetic Moments ◽  
Total Magnetic Moment ◽  
First Principle ◽  
Half Metallic ◽  
Heusler Compound ◽  
First Principle Calculations ◽  
Metallic Ferromagnet

Employing first-principle calculations, we investigated the influence of the impurity, Fe atom, on magnetism and electronic structures of Heusler compound Ti2CoSi, which is a spin gapless semiconductor (SGS). When the impurity, Fe atom, intervened, Ti2CoSi lost its SGS property. As TiA atoms (which locate at (0, 0, 0) site) are completely occupied by Fe, the compound converts to half-metallic ferromagnet (HMF) TiFeCoSi. During this SGS→HMF transition, the total magnetic moment linearly decreases as Fe concentration increases, following the Slate–Pauling rule well. When all Co atoms are substituted by Fe, the compound converts to nonmagnetic semiconductor Fe2TiSi. During this HMF→nonmagnetic semiconductor transition, when Fe concentration y ranges from y = 0.125 to y = 0.625, the magnetic moment of Fe atom is positive and linearly decreases, while those of impurity Fe and TiB (which locate at (0.25, 0.25, 0.25) site) are negative and linearly increase. When the impurity Fe concentration reaches up to y = 1, the magnetic moments of Ti, Fe, and Si return to zero, and the compound is a nonmagnetic semiconductor.

scholarly journals Origin of the Low Magnetic Moment in Fe2AlTi: An Ab Initio Study

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1732 ◽  
Author(s):  
Martin Friák ◽  
Anton Slávik ◽  
Ivana Miháliková ◽  
David Holec ◽  
Monika Všianská ◽  
...  
Keyword(s):  
Ab Initio ◽  
Magnetic Moment ◽  
Energy Surface ◽  
Magnetic Moments ◽  
Local Magnetic Moment ◽  
Spin Configuration ◽  
Spin Effects ◽  
Order Of Magnitude ◽  
Huge Impact ◽  
Insight Into

The intermetallic compound Fe 2 AlTi (alternatively Fe 2 TiAl) is an important phase in the ternary Fe-Al-Ti phase diagram. Previous theoretical studies showed a large discrepancy of approximately an order of magnitude between the ab initio computed magnetic moments and the experimentally measured ones. To unravel the source of this discrepancy, we analyze how various mechanisms present in realistic materials such as residual strain effects or deviations from stoichiometry affect magnetism. Since in spin-unconstrained calculations the system always evolves to the spin configuration which represents a local or global minimum in the total energy surface, finite temperature spin effects are not well described. We therefore turn the investigation around and use constrained spin calculations, fixing the global magnetic moment. This approach provides direct insight into local and global energy minima (reflecting metastable and stable spin phases) as well as the curvature of the energy surface, which correlates with the magnetic entropy and thus the magnetic configuration space accessible at finite temperatures. Based on this approach, we show that deviations from stoichiometry have a huge impact on the local magnetic moment and can explain the experimentally observed low magnetic moments.

Magnetization switching by magnon-mediated spin torque through an antiferromagnetic insulator

Science ◽  
2019 ◽  
Vol 366 (6469) ◽  
pp. 1125-1128 ◽  
Author(s):  
Yi Wang ◽  
Dapeng Zhu ◽  
Yumeng Yang ◽  
Kyusup Lee ◽  
Rahul Mishra ◽  
...  
Keyword(s):  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Spin Torque ◽  
Local Magnetization ◽  
Magnetization Switching ◽  
Spintronic Devices ◽  
Magnetic Devices ◽  
Alternative Approach ◽  
Efficient Control ◽  
Electrical Spin

Widespread applications of magnetic devices require an efficient means to manipulate the local magnetization. One mechanism is the electrical spin-transfer torque associated with electron-mediated spin currents; however, this suffers from substantial energy dissipation caused by Joule heating. We experimentally demonstrated an alternative approach based on magnon currents and achieved magnon-torque–induced magnetization switching in Bi2Se3/antiferromagnetic insulator NiO/ferromagnet devices at room temperature. The magnon currents carry spin angular momentum efficiently without involving moving electrons through a 25-nanometer-thick NiO layer. The magnon torque is sufficient to control the magnetization, which is comparable with previously observed electrical spin torque ratios. This research, which is relevant to the energy-efficient control of spintronic devices, will invigorate magnon-based memory and logic devices.

scholarly journals Ab-Initio Study of the Electronic and Magnetic Properties of Boron- and Nitrogen-Doped Penta-Graphene

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 816 ◽  
Author(s):  
Chao Zhang ◽  
Yu Cao ◽  
Xing Dai ◽  
Xian-Yong Ding ◽  
Leilei Chen ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Charge Transfer ◽  
First Principles ◽  
Magnetic Moments ◽  
First Principles Calculations ◽  
Electronic Band ◽  
Magnetic Devices ◽  
Spin Polarized ◽  
Electronic Band Gap ◽  
Transfer Mechanisms

First-principles calculations were performed to investigate the effects of boron/nitrogen dopant on the geometry, electronic structure and magnetic properties of the penta-graphene system. It was found that the electronic band gap of penta-graphene could be tuned and varied between 1.88 and 2.12 eV depending on the type and location of the substitution. Moreover, the introduction of dopant could cause spin polarization and lead to the emergence of local magnetic moments. The main origin of the magnetic moment was analyzed and discussed by the examination of the spin-polarized charge density. Furthermore, the direction of charge transfer between the dopant and host atoms could be attributed to the competition between the charge polarization and the atomic electronegativity. Two charge-transfer mechanisms worked together to determine which atoms obtained electrons. These results provide the possibility of modifying penta-graphene by doping, making it suitable for future applications in the field of optoelectronic and magnetic devices.

Magnetic Properties and Structural Transformation in Copper-304 Stainless Steel Multilayer Materials

1995 ◽  
Vol 382 ◽  
Author(s):  
K. Parvin ◽  
S.P. Weathersby ◽  
T.W. Barbee ◽  
T.P. Weihs ◽  
M.A. Wall
Keyword(s):  
Stainless Steel ◽  
Magnetic Moment ◽  
Magnetic Moments ◽  
High Volume ◽  
304 Stainless Steel ◽  
X Ray Diffraction ◽  
Multilayer Foils ◽  
Large Period ◽  
Fcc Phase ◽  
Bcc Phase

ABSTRACTMultilayer foils of Cu-304 stainless steel (304SS) with equal layer thicknesses in the range t=5.0-500 Å and total thicknesses 10-20 μm have been synthesized using magnetron sputtering at ambient substrate temperature. The x-ray diffraction data of as-deposited films show two structural regimes: small thickness (t=5-10 Å) which is characterized by epitaxial FCC growth of 304SS on copper, and large thickness (t=13.5-500 Å) which shows epitaxial FCC 304SS growth near the interface and BCC 304SS growth away from the interface. FCC structured films show very small magnetic moments at room temperature similar to bulk 304SS stable FCC phase. However, a strong magnetic moment is observed for thicker samples due to ferromagnetic metastable 304SS BCC phase. Two opposing transformations occur in the 304 layers as the samples are heated. The first transformation is from the metastable BCC 304SS to the stable FCC phase. This transformation produces a strong drop in magnetic moment and is clearly visible in the large period multilayers which contain high volume fractions of BCC 304SS. The second transformation is from the original FCC phase to a new stable BCC phase in the 304SS near the copper-304SS interfaces.The transformation is produced by diffusion of nickel from the 304SS into the surroundingcopper and the chemical destabilization of the FCC phase which starts near 400 ºC.This transformation produces a sharp increase in magnetic moment. The magnetic signal drops to zero near 675 ºC which is the Curie temperature of ferromagnetic BCC Fe.75 Cr25..

scholarly journals The Spin Periods of Magnetic Cataclysmic Variables

2004 ◽  
Vol 190 ◽  
pp. 216-229 ◽  
Author(s):  
A. J. Norton ◽  
R. V. Somerscales ◽  
G. A. Wynn
Keyword(s):  
Orbital Period ◽  
Magnetic Moment ◽  
White Dwarf ◽  
Magnetic Moments ◽  
Cataclysmic Variables ◽  
Intermediate Polars ◽  
Magnetic Cataclysmic Variables ◽  
Remarkable Agreement

AbstractWe have used a model of magnetic accretion to investigate the rotational equilibria of magnetic cataclysmic variables (MCVs). This has enabled us to derive a set of equilibrium spin periods as a function of orbital period and magnetic moment which we use to estimate the magnetic moments of all known intermediate polars. We further show how these equilibrium spin periods relate to the polar synchronisation condition and use these results to calculate the theoretical histogram describing the distribution of magnetic CVs as a function of Pspin/Porb. We demonstrate that this is in remarkable agreement with the observed distribution assuming that the number of systems as a function of white dwarf magnetic moment is distributed according to .

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