scholarly journals Magnetic properties of free-standing finite linear Co chains

2018 ◽  
Vol 64 (5) ◽  
pp. 483 ◽  
Author(s):  
Julio Cesar Hernandez-Herrejon ◽  
Rodrigo Chavez-Alcazar
Keyword(s):  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Density Functional ◽  
Finite Size ◽  
Anisotropy Energy ◽  
Spin Moment ◽  
Generalized Gradient ◽  
Free Standing ◽  
Magnetic Anisotropy Energy ◽  
Atomic Chains

The ground state magnetic properties of Co_N linear atomic chains with 1 ≤ N ≤ 10 are studied within density functional theory using the generalized gradient approximation . A linear scaling between the binding energy per atom and the inverse of the number of atoms in the chain is found. For the optimized geometries, our results show a dimerization effect for chains of few atoms but for bigger ones the phenomena disappear in the center but remains at the ends due to finite size effects. The spin moment, the orbital moment and the magnetic anisotropy energy were investigated. For large chains, the orbital and spin moments have a tendency to become uniform. Enhanced spin and orbital moments were found due to the reduced coordination number compared to the cobalt in bulk. The cobalt chain of five atoms has the biggest magnetic anisotropy energy with an outstanding 8 meV, suggesting that it could have applications in ultrahigh density magnetic memories and hard disk. 

Comparison between Magnetic Anisotropy Energy and a Parameter to the Assessment of Magnetic Property of Electrical Steel

2018 ◽  
Vol 930 ◽  
pp. 449-453
Author(s):  
R.A.C. Felix ◽  
R.L.O. da Rosa ◽  
Luiz P. Brandão
Keyword(s):  
Magnetic Properties ◽  
Magnetic Property ◽  
Magnetic Anisotropy ◽  
Electrical Steel ◽  
Anisotropy Energy ◽  
Alternative Methods ◽  
Magnetic Polarization ◽  
Magnetic Anisotropy Energy ◽  
Electrical Steels ◽  
Global Parameters

Alternative methods of quantitative texture analysis are applied to characterize the non-oriented grain electrical steels (NOG) in relation to their magnetic properties. Magnetic anisotropy energy (Ea) and A parameter are two models based on crystallographic texture that generates global parameters that can be used to predict the magnetic properties of NOG steels. In this work, these two models were used to evaluate the magnetic polarization and compared between themselves to realize which one best correlates to this property.

scholarly journals Electronic structure and magnetic properties of solids

2005 ◽  
Vol 220 (5/6) ◽  
Author(s):  
Sergej Y. Savrasov ◽  
Antonina Toropova ◽  
Mikhail I. Katsnelson ◽  
Alexander I. Lichtenstein ◽  
Vladimir Antropov ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
Magnetic Anisotropy ◽  
Spin Wave ◽  
Anisotropy Energy ◽  
Computational Techniques ◽  
Wave Spectra ◽  
Temperature Dependent ◽  
Magnetic Anisotropy Energy ◽  
Magnetic Susceptibilities

AbstractWe review basic computational techniques for simulations of various magnetic properties of solids. Several applications to compute magnetic anisotropy energy, spin wave spectra, magnetic susceptibilities and temperature dependent magnetisations for a number of real systems are presented for illustrative purposes.

scholarly journals Magnetic anisotropy and stability of Fe3Ga compounds

2021 ◽  
Vol 5 (4) ◽  
pp. 229-235
Author(s):  
T. M. Inerbaev ◽  
A. U. Abuova ◽  
A. K. Dauletbekova ◽  
F. U. Abuova ◽  
G. A. Kaptagay ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Density Functional ◽  
Anisotropy Energy ◽  
Magnetic Anisotropy Energy ◽  
Phonon Spectra ◽  
The Density Functional Theory ◽  
The Difference ◽  
Structure Lead ◽  
The Stability ◽  
Crystal Modifications

The magnetic anisotropy energy and the stability of crystal modifications of D03 and L21 of Fe3Ga compounds are studied with the density functional theory methods. The magnetic anisotropy energy of the D03 structure is more than twice the same value for the L21 structure. The features in the electronic structure lead to the difference in the magnitude of spin-orbit interaction, explaining the found effect. The L21 structure is more thermodynamically stable in the entire range of the considered pressures. Under pressure, the considered crystal modifications of Fe3Ga lose their stability due to the appearance of imaginary frequencies in their phonon spectra.

Magnetic Properties and L10 Phase Formation in CoPt Nanoparticles

2012 ◽  
Vol 190 ◽  
pp. 159-162 ◽  
Author(s):  
S.V. Komogortsev ◽  
N.A. Chizhik ◽  
E.Y. Filatov ◽  
S.V. Korenev ◽  
Y.V. Shubin ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Phase Formation ◽  
Annealing Time ◽  
Anisotropy Energy ◽  
Domain Formation ◽  
Magnetic Anisotropy Energy

The effect of the atomic disorderorder transformation on remanence, coercivity and magnetic anisotropy energy in CoPt nanoparticles prepared by thermal decomposition and annealed at 400°C for 4 and 16 hours has been studied. The observed remanence and magnetic anisotropy energy enhancement versus annealing time are discussed in the terms of ordering domain formation inside nanoparticles.

scholarly journals First-principles investigation of half-metallic ferromagnetism of Fe2YSn (Y = Mn, Ti and V) Heusler alloys

2021 ◽  
Vol 24 (2) ◽  
pp. 23703
Author(s):  
M. Sayah ◽  
S. Zeffane ◽  
M. Mokhtari ◽  
F. Dahmane ◽  
L. Zekri ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
First Principles ◽  
Density Functional ◽  
Heusler Alloys ◽  
Type Structure ◽  
Spin Moment ◽  
Generalized Gradient ◽  
Half Metallic ◽  
Electronic And Magnetic Properties ◽  
The Density Functional Theory

In this paper, we use the first-principles calculations based on the density functional theory to investigate structural, electronic and magnetic properties of Fe2YSn with (Y = Mn, Ti and V). The generalized gradient approximation (GGA) method is used for calculations. The Cu2MnAl type structure is energetically more stable than the Hg2CuTi type structure. The negative formation energy is shown as the evidence of thermodynamic stability of the alloy. The calculated total spin moment is found as 3μB and 0μB at the equilibrium lattice constant for Fe2MnSn and Fe2TiSn respectively, which agrees with the Slater-Pauling rule of Mt= Zt-24. The study of electronic and magnetic properties proves that Fe2MnSn and Fe2TiSn full-Heusler alloys are complete half-metallic ferromagnetic materials.

scholarly journals Structural, electronic and magnetic properties of Fe, Co, Ni monatomic nanochains encapsulated in armchair LiF nanotubes

2017 ◽  
Vol 35 (2) ◽  
pp. 283-290
Author(s):  
B. Arghavani Nia ◽  
R. Moradian ◽  
M. Shahrokhi
Keyword(s):  
Magnetic Properties ◽  
Spin Polarization ◽  
Magnetic Moment ◽  
Density Functional ◽  
Magnetic Nanostructures ◽  
Spin Splitting ◽  
Total Density ◽  
Generalized Gradient ◽  
Electronic And Magnetic Properties ◽  
Atomic Chains

Abstract Structural, electronic and magnetic properties of transition metal TM (TM = Fe, Co and Ni) atomic chains wrapped in single walled LiF armchair nanotubes have been investigated by the first-principles calculations in the framework of the density functional theory. The generalized gradient approximation (GGA) with Hubbard repulsion potential and without Hubbard repulsion was employed to describe the exchange-correlation potential. It is found that all these TM chains @LiFNTs systems have negative formation energy so they are stable and exothermic. Total density of states and partial densities of states analyses show that the spin polarization and the magnetic moment of TM chains @LiFNTs(n,n) systems come mostly from the TM atom chains. All these nanocomposites are ferromagnetic (FM) and spin splitting between spin up and down is observed. The high magnetic moment and spin polarization of the TM chains @LiFNT(n,n) systems show that they can be used as magnetic nanostructures possessing potential current and future applications in permanent magnetism, magnetic recording, and spintronics.

scholarly journals Anatomy of Magnetic Anisotropy and Voltage-Controlled Magnetic Anisotropy in Metal Oxide Heterostructure from First Principles

Crystals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1118
Author(s):  
Indra Pardede ◽  
Daiki Yoshikawa ◽  
Tomosato Kanagawa ◽  
Nurul Ikhsan ◽  
Masao Obata ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Density Functional ◽  
Compressive Strain ◽  
Magnetic Tunnel Junction ◽  
Dipole Interaction ◽  
Anisotropy Energy ◽  
Strain Effect ◽  
Spin Orbit ◽  
Magnetic Anisotropy Energy ◽  
Oxide Heterostructure

Voltage control of magnetic anisotropy (VCMA) is one of the promising approaches for magnetoelectric control of magnetic tunnel junction (MTJ). Here, we systematically calculated the magnetic anisotropy (MA) and the VCMA energies in the well-known MTJ structure consisting of Fe/MgO interface with Cr buffer layer. In this calculation, we investigated an alloying between Fe and Cr and a strain effect. We used a spin density functional approach which includes both contributions from magnetocrystalline anisotropy energy (MCAE) originating from spin–orbit coupling and shape magnetic anisotropy energy from spin dipole–dipole interaction. In the present approach, the MCAE part, in addition to a common scheme of total energy, was evaluated using a grand canonical force theorem scheme. In the latter scheme, atom-resolved and k-resolved analyses for MA and VCMA can be performed. At first, we found that, as the alloying is introduced, the perpendicular MCAE increases by a factor of two. Next, as the strain is introduced, we found that the MCAE increases with increasing compressive strain with the maximum value of 2.2 mJ/m2. For the VCMA coefficient, as the compressive strain increases, the sign becomes negative and the absolute value becomes enhanced to the number of 170 fJ/Vm. By using the atom-resolved and k-resolved analyses, we clarified that these enhancements of MCAE and VCMA mainly originates from the Fe interface with MgO (Fe1) and are located at certain lines in the two dimensional Brillouin zone. The findings on MCAE and VCMA are fully explained by the spin-orbit couplings between the certain d-orbital states in the second-order perturbation theory.

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