Evaluation of energy filtering effect from first principles calculations

2016 ◽  
Vol 213 (12) ◽  
pp. 3250-3253 ◽  
Author(s):  
Xi Zhao ◽  
Xiu-hong Zhu ◽  
Rui-zhi Zhang
Keyword(s):  
First Principles ◽  
First Principles Calculations ◽  
Energy Filtering ◽  
Filtering Effect

scholarly journals Strong spin-filtering and spin-valve effects in a molecular V–C60–V contact

2012 ◽  
Vol 3 ◽  
pp. 589-596 ◽  
Author(s):  
Mohammad Koleini ◽  
Mads Brandbyge
Keyword(s):  
Electronic Properties ◽  
Electronic Transport ◽  
First Principles ◽  
Spin Valve ◽  
Spin Coupling ◽  
First Principles Calculations ◽  
Filtering Effect ◽  
Majority Spin ◽  
Strong Spin ◽  
Spin Filtering

Motivated by the recent achievements in the manipulation of C60 molecules in STM experiments, we study theoretically the structure and electronic properties of a C60 molecule in an STM tunneljunction with a magnetic tip and magnetic adatom on a Cu(111) surface using first-principles calculations. For the case of a vanadium tip/adatom, we demonstrate how spin coupling between the magnetic V atoms, mediated by the C60, can be observed in the electronic transport, which display a strong spin-filtering effect, allowing mainly majority-spin electrons to pass (>95%). Moreover, we find a significant change in the conductance between parallel and anti-parallel spin polarizations in the junction (86%) which suggests that STM experiments should be able to characterize the magnetism and spin coupling for these systems.

Study on Spin Transport Properties in Transition Metal Atoms Interfered Alpha-Graphyene Nanoribbon Systems

2014 ◽  
Vol 1015 ◽  
pp. 389-392
Author(s):  
Y.H. Zhou ◽  
L.L. Zhou ◽  
X.H. Qiu ◽  
Y.L. Peng
Keyword(s):  
Transition Metal ◽  
Transport Properties ◽  
First Principles ◽  
Differential Resistance ◽  
First Principles Calculations ◽  
Metal Atoms ◽  
Transition Metal Atoms ◽  
Filtering Effect ◽  
Proper Analysis ◽  
Spin Filtering

The transport properties of transition metal atoms interfered alpha-graphyne nanoribbon systems are investigated by first-principles calculations combined with the Keldysh nonequilibrium Green’s method. In all, five types of configurations are considered. We find that intervention of three Cr atom in alpha-graphyne nanoribbon systems decreases the conductivity of the system. Further study show that the magnetic direction of the electrode infulence the spin filtering effect greatly, while the ralative magnetic direction of the three transition Cr atoms have little effect on the transport properties. At finite bias window, negative differential resistance happens. Proper analysis are given to explain the spin filtering phenonmenon and the different transport properties via transmission coefficient and projected density of states.

Spintronic Transport Performances of VSe2 Nanoribbons

2020 ◽  
Vol 15 (2) ◽  
pp. 269-275
Author(s):  
Wei-Chao Zhang ◽  
Wei-Feng Sun
Keyword(s):  
Bias Voltage ◽  
Electronic Transport ◽  
First Principles ◽  
Negative Differential Resistance ◽  
Differential Resistance ◽  
Transmission Spectra ◽  
First Principles Calculations ◽  
Spintronic Devices ◽  
Crystal Anisotropy ◽  
Filtering Effect

The spin-resolved electronic transport behaviors of VSe2 nanoribbons are theoretically investigated to explore their applications in spintronic devices, employing by the first-principles calculations combined with nonequilibrium Green's function scheme. The band structure, current varying curves with bias voltage between nanoribbon terminal electrodes and electronic transmission spectra of two representative VSe2 nanoribbons along zigzag and armchair crystallographic orientations are calculated respectively. The evident negative differential resistance under the bias voltage of ∼0.6 V for the armchair orientation has been found, implying the significant crystal anisotropy of VSe2 monolayer. Meanwhile, both the VSe2 nanoribbon devices along zigzag and armchair directions represent favorable spin filtering effect, suggesting they are prospective candidates as a multifunction material in spintronic and digital applications.

Electronic Structure and X-ray Absorption Spectra of Rutile TiO2 Using First-Principles Calculations

2014 ◽  
Vol 52 (12) ◽  
pp. 1025-1029
Author(s):  
Min-Wook Oh ◽  
Tae-Gu Kang ◽  
Byungki Ryu ◽  
Ji Eun Lee ◽  
Sung-Jae Joo ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Absorption Spectra ◽  
First Principles ◽  
First Principles Calculations ◽  
Rutile Tio2 ◽  
X Ray ◽  
X Ray Absorption

To Bend or Not to Bend, the Dilemma of Multiple Bonds

2019 ◽  
Author(s):  
Michele Pizzocchero ◽  
Matteo Bonfanti ◽  
Rocco Martinazzo
Keyword(s):  
First Principles ◽  
2D Materials ◽  
Main Group ◽  
First Principles Calculations ◽  
Group 14 ◽  
Multiple Bonds ◽  
Main Group Elements ◽  
Structural Distortions

The manuscript addresses the issue of the structural distortions occurring at multiple bonds between high main group elements, focusing on group 14. These distortions are known as trans-bending in silenes, disilenes and higher group analogues, and buckling in 2D materials likes silicene and germanene. A simple but correlated \sigma + \pi model is developed and validated with first-principles calculations, and used to explain the different behaviour of second- and higher- row elements.

Thermodynamic Stability of Hexagonal and Rhombohedral Bn at Cvd Conditions from Van der Waals Corrected First Principles Calculations

2019 ◽  
Author(s):  
Henrik Pedersen ◽  
Björn Alling ◽  
Hans Högberg ◽  
Annop Ektarawong
Keyword(s):  
Thin Films ◽  
Thermodynamic Stability ◽  
First Principles ◽  
Thermal Equilibrium ◽  
Density Functional ◽  
Van Der Waals ◽  
Chemical Vapor ◽  
First Principles Calculations ◽  
Functional Theory ◽  
The Stability

Thin films of boron nitride (BN), particularly the sp<sup>2</sup>-hybridized polytypes hexagonal BN (h-BN) and rhombohedral BN (r-BN) are interesting for several electronic applications given band gaps in the UV. They are typically deposited close to thermal equilibrium by chemical vapor deposition (CVD) at temperatures and pressures in the regions 1400-1800 K and 1000-10000 Pa, respectively. In this letter, we use van der Waals corrected density functional theory and thermodynamic stability calculations to determine the stability of r-BN and compare it to that of h-BN as well as to cubic BN and wurtzitic BN. We find that r-BN is the stable sp<sup>2</sup>-hybridized phase at CVD conditions, while h-BN is metastable. Thus, our calculations suggest that thin films of h-BN must be deposited far from thermal equilibrium.

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