scholarly journals First-Principles Prediction of Skyrmionic Phase Behavior in GdFe2 Films Capped by 4d and 5d Transition Metals

2019 ◽  
Vol 9 (4) ◽  
pp. 630 ◽  
Author(s):  
Soyoung Jekal ◽  
Andreas Danilo ◽  
Dao Phuong ◽  
Xiao Zheng
Keyword(s):  
Transition Metals ◽  
Density Functional ◽  
Spin Dynamic ◽  
Zero Magnetic Field ◽  
Spin Orbit Coupling ◽  
Dynamic Simulations ◽  
Functional Theory ◽  
Spin Spiral ◽  
Moriya Interaction ◽  
Spiral Phase

In atomic GdFe 2 films capped by 4d and 5d transition metals, we show that skyrmions with diameters smaller than 12 nm can emerge. The Dzyaloshinskii–Moriya interaction (DMI), exchange energy, and the magnetocrystalline anisotropy (MCA) energy were investigated based on density functional theory. Since DMI and MCA are caused by spin–orbit coupling (SOC), they are increased with 5d capping layers which exhibit strong SOC strength. We discover a skyrmion phase by using atomistic spin dynamic simulations at small magnetic fields of ∼1 T. In addition, a ground state that a spin spiral phase is remained even at zero magnetic field for both films with 4d and 5d capping layers.

scholarly journals First-Principles Prediction of Skyrmionic Phase Behavior in GdFe$_2$ Films Capped by 4$D$ and 5$D$ Transition Metals

2019 ◽  
Author(s):  
Soyoung Jekal ◽  
Andreas Danilo ◽  
Dao Phoung ◽  
Xiao Zheng
Keyword(s):  
Transition Metals ◽  
Density Functional ◽  
Spin Dynamic ◽  
Zero Magnetic Field ◽  
Spin Orbit Coupling ◽  
Dynamic Simulations ◽  
Functional Theory ◽  
Spin Spiral ◽  
Moriya Interaction ◽  
Spiral Phase

In atomic GdFe$_2$ films capped by 4$d$ and 5$d$ transition metals, we show that skyrmions with diameters smaller than 12 nm can emerge. The Dzyaloshinskii--Moriya interaction (DMI), exchange energy, and the magnetocrystalline anisotropy (MCA) energy were investigated based on density functional theory. Since DMI and MCA are caused by spin--orbit coupling (SOC), they are increased with 5$d$ capping layers which exhibit strong SOC strength. We discover a skyrmion phase by using atomistic spin dynamic simulations at small magnetic fields of $\sim$1 T. In addition, a ground state that a spin spiral phase is remained even at zero magnetic field for both films with 4$d$ and 5$d$ capping layers.

scholarly journals First-Principles Prediction of Skyrmionic Phase Behavior in GdFe$_2$ Films Capped by 4$D$ and 5$D$ Transition Metals

2019 ◽  
Author(s):  
Soyoung Jekal ◽  
Andreas Danilo ◽  
Dao Phuong ◽  
Xiao Zheng
Keyword(s):  
Transition Metals ◽  
Density Functional ◽  
Spin Dynamics ◽  
Zero Magnetic Field ◽  
Spin Orbit Coupling ◽  
Functional Theory ◽  
Dynamics Simulations ◽  
Spin Spiral ◽  
Moriya Interaction ◽  
Spiral Phase

In atomic GdFe$_2$ films capped by 4$d$ and 5$d$ transition metals, we show that skyrmions with extremely reduced diameters of a smaller than 12 nm can occur. The Dzyaloshinskii-Moriya interaction (DMI), exchange energy, and the magnetocrystalline anisotropy (MCA) energy were investigated based on density functional theory. Since DMI and MCA are caused by spin-orbit coupling, they are increased with 5$d$ capping layers compared to films capped by 4$d$ transition metal. We discovered a skyrmion phase by using atomistic spin dynamics simulations at small magnetic fields of $\sim$ 1 T. A ground state that a spin spiral phase is remained even at zero magnetic field for both films with 4$d$ and 5$d$ capping layers.

scholarly journals A Free Aluminylene with Diverse σ-Donating and Doubly σ/π-Accepting Ligand Features for Transition Metals

2021 ◽  
Author(s):  
Xin Zhang ◽  
Liu Leo Liu
Keyword(s):  
Density Functional Theory ◽  
Coordination Chemistry ◽  
Transition Metals ◽  
Electronic Structures ◽  
Ligand Exchange ◽  
Density Functional ◽  
Reduction Reaction ◽  
Functional Theory ◽  
Metal Centers ◽  
Coordination Behavior

We report herein the synthesis, characterization, and coordination chemistry of a free N-aluminylene, namely a carbazolylaluminylene 2b. This species is prepared via a reduction reaction of the corresponding carbazolyl aluminium diiodide. The coordination behavior of 2b towards transition metal centers (W, Cr) is shown to afford a series of novel aluminylene complexes 3-6 with diverse coordination modes. We demonstrate that the Al center in 2b can behave as: 1. a σ-donating and doubly π-accepting ligand; 2. a σ-donating, σ-accepting and π-accepting ligand; and 3. a σ-donating and doubly σ-accepting ligand. Additionally, we show ligand exchange at the aluminylene center providing access to the modulation of electronic properties of transition metals without changing the coordinated atoms. Investigations of 2b with IDippCuCl (IDipp = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) show an unprecedented aluminylene-alumanyl transformation leading to a rare terminal Cu-alumanyl complex 8. The electronic structures of such complexes and the mechanism of the aluminylene-alumanyl transformation are investigated through density functional theory (DFT) calculations.

Are luminescent Ru2+ chelated complexes selective coordinative sensors for the detection of heavy cations ?

2021 ◽  
Author(s):  
Christophe Gourlaouen ◽  
Benjamin Schweitzer ◽  
Chantal Daniel
Keyword(s):  
Density Functional Theory ◽  
Transition Metals ◽  
Density Functional ◽  
Functional Theory ◽  
Group 12

The ability of [Ru(bpy)2(bpym)]2+ (bpy = 2,2’-biprydine; bpym = 2,2’-bipyrimidine) at probing specifically heavy cations has been investigated by means of density functional theory for transition metals, group 12 elements...

First-principles study of BiFeO3 and BaTiO3 in tetragonal structure

2019 ◽  
Vol 33 (21) ◽  
pp. 1950231
Author(s):  
Akbar Ali ◽  
Imad Khan ◽  
Zahid Ali ◽  
Fawad Khan ◽  
Iftikhar Ahmad
Keyword(s):  
Density Functional ◽  
Coupling Effect ◽  
Ferroelectric Materials ◽  
Bandgap Energy ◽  
Spin Orbit Coupling ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Exchange Correlation ◽  
Total Energies ◽  
A Site

Structural, electronic, magnetic and mechanical properties of the perovskites BiFeO3 (BFO) and BaTiO3 (BTO) are investigated using density functional theory (DFT). Structural and mechanical parameters are calculated using generalized gradient approximation (GGA) and the results consistent with the available literature. The stable magnetic phases are achieved by optimizing total energies versus volumes of the cells in different magnetic configurations such as nonmagnetic (NM), ferromagnetic (FM) and antiferromagnetic (AFM). BTO is found to be NM while BFO favors G-type AFM (G-AFM) phase. The electronic properties are investigated using GGA, GGA with Hubbard potential (GGA[Formula: see text]+[Formula: see text]U) and modified Becke–Johnson (GGA-mBJ) exchange–correlation functionals. BFO is found to be a direct bandgap semiconductor having gap energy value 3.0 eV whereas BTO is an indirect semiconductor with bandgap energy 2.9 eV. Spin–orbit coupling effect is dominant in BFO due to the larger size of A-site cation. The electrical polarization shows that both the compounds are ferroelectric materials with significant spontaneous polarization of 144.1 [Formula: see text]C/cm2 and 27.9 [Formula: see text]C/cm2 for BFO and BTO respectively.

Ti and Zr Transition Metals Effect in the D03 Fe3Al by Ab Initio Study Approach

2014 ◽  
Vol 783-786 ◽  
pp. 1640-1645
Author(s):  
Jean Marc Raulot ◽  
S. Chentouf ◽  
T. Grosdidier ◽  
Hafid Aourag
Keyword(s):  
Molecular Dynamics ◽  
Transition Metals ◽  
Ab Initio ◽  
Density Functional ◽  
Ab Initio Molecular Dynamics ◽  
Effect Of Temperature ◽  
Site Preference ◽  
Functional Theory ◽  
Study Approach

The effect of the Ti and Zr transition metals on the D03-Fe3Al intermetallic compounds has been investigated by means of ab initio Pseudo Potentials numerical simulations based on Density Functional Theory. Two main issues will be addressed the understanding of the role of these two transition metals in terms of stability of the bulk at the light of their site preference in the D03-Fe3Al structure the behaviour of Ti and Zr transition metals in the sigma 5 (310) [001] grain boundary and their effect on the structural stability of this interface. An important issue when studying these aspects is to take into accounts the effect of temperature. This requires a molecular dynamics treatment of the atoms in the supercell. The technique known as ab initio molecular dynamics (AIMD) solves these problems by combining ‘on the fly’ electronic structure calculations with finite temperature dynamics. Thus, our study was conducted both using the conventional static ab initio calculations (0K) as well as by taking into account the effect of temperature (Ab Initio Molecular Dynamics).

Cubic MgH2 stabilized by alloying with transition metals: A density functional theory study

2008 ◽  
Vol 56 (13) ◽  
pp. 2948-2954 ◽  
Author(s):  
B.R. Pauw ◽  
W.P. Kalisvaart ◽  
S.X. Tao ◽  
M.T.M. Koper ◽  
A.P.J. Jansen ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Transition Metals ◽  
Density Functional ◽  
Density Functional Theory Study ◽  
Functional Theory
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