scholarly journals Theoretical Study of Spin Conduction in the Ni/DTE/Ni Nanohybrid

Nano Hybrids ◽  
2013 ◽  
Vol 4 ◽  
pp. 1-20 ◽  
Author(s):  
Kanchan Ulman ◽  
Mighfar Imam ◽  
Shobhana Narasimhan ◽  
Anders Odell ◽  
Anna Delin
Keyword(s):  
Density Functional ◽  
Transmission Function ◽  
Spin Current ◽  
Functional Theory ◽  
Contact Materials ◽  
Spin Polarized ◽  
Interesting Candidate ◽  
High Bias ◽  
Conductance Ratio ◽  
Magneto Resistance

The photoswitching molecule dithienylethene (DTE) is an interesting candidate for constructing optoelectronic molecular devices since it can be made to switch between a closed and an open conformation using light. We here report computations, based on density functional theory (DFT) and the non-equilibrium Green function (NEGF) method, of the spin-resolved conductance of the two DTE isomers attached to spin-polarized nickel leads. Results are compared and contrasted to those of other contact materials (nonmagnetic Ni, Ag, and Au), analyzing the physical origins of the various features in the transmission function. It was found rather surprisingly, that the two spin channels in the Ni/DTE/Ni device have almost identical I-V characteristics, despite one channel being d-dominated and the other one s-dominated. It was also observed that the Ni-based device exhibits a sustained high conductance ratio also for high bias - a property that may be of relevance in future device design. Furthermore, two computational schemes for calculating the conductance were compared and analyzed. It was found that even for very small bias the molecular orbital polarization was decisive for spin-related properties such as the spin current ratio and magneto-resistance in the Ni/DTE/Ni device.

scholarly journals Effect of Twisting and Stretching on Magneto Resistance and Spin Filtration in CNTs

2017 ◽  
Author(s):  
Anil Kumar Singh ◽  
Sudhanshu Choudhary
Keyword(s):  
Density Functional Theory ◽  
Carbon Nanotube ◽  
Transport Properties ◽  
Quantum Transport ◽  
Density Functional ◽  
Spin Transport ◽  
Functional Theory ◽  
Higher Spin ◽  
High Bias ◽  
Magneto Resistance

Spin dependent quantum transport properties in twisted carbon nanotube and stretched carbon nanotube are calculated using density functional theory (DFT) and non-equilibrium green’s function (NEGF) formulation. Twisting and stretching have no effect on spin transport in CNTs at low bias voltages. However, at high bias voltages the effects are significant. Stretching restricts any spin-up current in antiparallel configuration (APC) which results in higher magneto resistance (MR). Twisting allows spin-up current almost equivalent to the pristine CNT case resulting in lower MR. High spin filtration is observed in PC and APC for pristine, stretched and twisted structures at all applied voltages. In APC, at low voltages spin filtration in stretched CNT is higher than in pristine and twisted ones with pristine giving higher spin filtration than twisted CNT.

Photogalvanic effect induced fully spin polarized current and pure spin current in zigzag SiC nanoribbons

2018 ◽  
Vol 20 (41) ◽  
pp. 26744-26751 ◽  
Author(s):  
Jun Chen ◽  
Liwen Zhang ◽  
Lei Zhang ◽  
Xiaohong Zheng ◽  
Liantuan Xiao ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Green's Function ◽  
First Principles ◽  
Density Functional ◽  
Spin Current ◽  
Pure Spin ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Photogalvanic Effect ◽  
Spin Polarized

Using nonequilibrium Green's function combined with density functional theory, we investigate the spin-related current generated by the photogalvanic effect (PGE) in monolayer zigzag SiC nanoribbons (ZSiCNRs) by first-principles calculations.

scholarly journals Pd/Pt embedded CN monolayers as efficient catalysts for CO oxidation

2019 ◽  
Vol 21 (46) ◽  
pp. 25743-25748
Author(s):  
Yong-Chao Rao ◽  
Xiang-Mei Duan
Keyword(s):  
Density Functional Theory ◽  
Co Oxidation ◽  
Density Functional ◽  
Carbon Nitride ◽  
Density Functional Theory Calculations ◽  
Catalytic Performance ◽  
Functional Theory ◽  
Spin Polarized ◽  
Planar Carbon

The catalytic performance of Pd/Pt embedded planar carbon nitride for CO oxidation has been investigated via spin-polarized density functional theory calculations.

scholarly journals Breathing distortions in the metallic, antiferromagnetic phase of LaNiO$_3$

2018 ◽  
Vol 5 (3) ◽  
Author(s):  
Alaska Subedi
Keyword(s):  
Density Functional ◽  
Recent Observation ◽  
Quantum Critical Point ◽  
Three Dimensional ◽  
Density Functional Theory Calculations ◽  
Antiferromagnetic Phase ◽  
Functional Theory ◽  
Antiferromagnetic Ordering ◽  
Spin Polarized ◽  
Structural Fluctuations

I study the structural and magnetic instabilities in LaNiO_33 using density functional theory calculations. From the non-spin-polarized structural relaxations, I find that several structures with different Glazer tilts lie close in energy. The PnmaPnma structure is marginally favored compared to the R\overline{3}cR3¯c structure in my calculations, suggesting the presence of finite-temperature structural fluctuations and a possible proximity to a structural quantum critical point. In the spin-polarized relaxations, both structures exhibit the \uparrow\!\!0\!\!\downarrow\!\!0↑0↓0 antiferromagnetic ordering with a rock-salt arrangement of the octahedral breathing distortions. The energy gain due to the breathing distortions is larger than that due to the antiferromagnetic ordering. These phases are semimetallic with small three-dimensional Fermi pockets, which is largely consistent with the recent observation of the coexistence of antiferromagnetism and metallicity in LaNiO_33 single crystals by Guo et al. [Nat. Commun. 9, 43 (2018)].

Density functional theory calculations of atomic, electronic and thermodynamic properties of cubic LaCoO3and La1−xSrxCoO3surfaces

RSC Advances ◽  
2015 ◽  
Vol 5 (1) ◽  
pp. 760-769 ◽  
Author(s):  
Shuguang Zhang ◽  
Ning Han ◽  
Xiaoyao Tan
Keyword(s):  
Density Functional Theory ◽  
Thermodynamic Properties ◽  
Dft Calculations ◽  
Phase Diagrams ◽  
Thermodynamic Stability ◽  
Electronic Structures ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Spin Polarized

Spin-polarized DFT calculations were used to investigate the atomic, electronic structures of LaCoO3and La1−xSrxCoO3surfaces. The thermodynamic stability of these surfaces was analyzed with phase diagrams. Influence of Sr-doping was also examined.

scholarly journals Stability and mobility of supported Nin (n = 1–10) clusters on ZrO2(111) and YSZ(111) surfaces: a density functional theory study

2018 ◽  
Vol 208 ◽  
pp. 87-104 ◽  
Author(s):  
Abdelaziz Cadi-Essadek ◽  
Alberto Roldan ◽  
Nora H. de Leeuw
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Spin Polarized ◽  
Ni Clusters

We have used spin polarized density functional theory (DFT) to evaluate the geometrical resilience of Ni clusters on ZrO2(111) and YSZ(111).

scholarly journals Discontinuous Behavior of the Pauli Potential in Density Functional Theory as a Function of the Electron Number

2019 ◽  
Author(s):  
Eli Kraisler ◽  
Axel Schild
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Electron Systems ◽  
Electron Number ◽  
Functional Theory ◽  
Fractional Number ◽  
Finite Systems ◽  
Pauli Potential ◽  
Spin Polarized ◽  
Orbital Free

<div>The Pauli potential is an essential quantity in orbital-free density-functional theory (DFT) and in the exact electron factorization (EEF) method for many-electron systems. Knowledge of the Pauli potential allows the description of a system relying on the density alone, without the need to calculate the orbitals.</div><div>In this work we explore the behavior of the exact Pauli potential in finite systems as a function of the number of electrons, employing the ensemble approach in DFT. Assuming the system is in contact with an electron reservoir, we allow the number of electrons to vary continuously and to obtain fractional as well as integer values. We derive an expression for the Pauli potential for a spin-polarized system with a fractional number of electrons and find that when the electron number surpasses an integer, the Pauli potential jumps by a spatially uniform constant, similarly to the Kohn-Sham potential. The magnitude of the jump equals the Kohn-Sham gap. We illustrate our analytical findings by calculating the exact and approximate Pauli potentials for Li and Na atoms with fractional numbers of electrons.</div>

Strain modulation on spin transport properties of PTB junction with MoC2 electrodes

2021 ◽  
Author(s):  
Yaoxing Sun ◽  
Bei Zhang ◽  
shidong zhang ◽  
Dan Zhang ◽  
Jiwei Dong ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electron Transport ◽  
Transport Properties ◽  
Density Functional ◽  
Spin Transport ◽  
Functional Theory ◽  
Spintronic Devices ◽  
Spin Polarized ◽  
Electron Transport Properties ◽  
Strain Modulation

Based on MoC2 nanoribbons and poly-(terphenylene-butadiynylene) (PTB) molecules, we designed MoC2-PTB molecular spintronic devices and investigated their spin-dependent electron transport properties by using spin-polarized density functional theory and non-equilibrium Green's...

scholarly journals The Magnetic Band-Structures of Ordered PtxFe1−x, PtxCo1−x, and PtxNi1−x (x = 0.25, 0.50, and 0.75)

2020 ◽  
Vol 6 (4) ◽  
pp. 61
Author(s):  
Ian Shuttleworth
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
High Symmetry ◽  
Band Structures ◽  
Electronic Band ◽  
Functional Theory ◽  
Ni Alloys ◽  
Spin Polarized ◽  
Electronic Band Structures

The electronic band structures of the ordered L12 and L10 phases of the PtxM1−x (M = Fe, Co and Ni) alloys were investigated using spin-polarized density functional theory (DFT). The relative contributions of both itinerant (Stoner) and localized magnetism at the high-symmetry k-points were determined and discussed qualitatively. Significant directional effects were identified along the A and R directions of the L10 and L12 alloys, respectively, and are discussed in terms of charge channeling effects.

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