scholarly journals Spin-Transport Tuning of Individual Magnetic Mn-Salophen Molecule via Chemical Adsorption

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1747 ◽  
Author(s):  
Feifei Li ◽  
Jing Huang ◽  
Jianing Wang ◽  
Qunxiang Li
Keyword(s):  
Single Molecule ◽  
Magnetic Moment ◽  
Density Functional ◽  
Spin Transport ◽  
Density Functional Theory Calculations ◽  
Chemical Adsorption ◽  
Adsorption Effect ◽  
Single Molecule Level ◽  
Filtering Effect ◽  
Spin Filtering

Control over spin states at the single molecule level is a key issue in the emerging field of molecular spintronics. Here, we explore the chemical adsorption effect on the magnetic and spin-transport properties of individual magnetic molecule by performing extensive density functional theory calculations in combining with non-equilibrium Green’s function method. Theoretical results clearly reveal that the molecular magnetic moment of Mn-salophen can be effectively tuned by adsorbing F and CO on the central Mn cation, while the adsorbed NO molecule quenches the molecular magnetic moment. Without chemical adsorption, the currents through Mn-salophen molecular junction just show a little distinction for two spin channels, which agrees well with previous investigation. Remarkably, the conductive channel can be switched from the spin-up electrons to the spin-down electrons via adsorbing F and CO, respectively, and the corresponding two Mn-salophen molecular junctions with chemical modifications display nearly perfect spin-filtering effect. The observed spin switch and the predicted spin-filtering effect via chemical adsorption indicates that Mn-salophen holds potential applications in molecular spintronic devices.

Fine Spin Filtering Effect in Co-Phthalocyanine Molecule Induced by the Spin Polarization of Co Atom

2014 ◽  
Vol 597 ◽  
pp. 127-130
Author(s):  
Yan Hong Zhou ◽  
X.H. Qiu ◽  
L.L. Zhou ◽  
Y.L. Peng
Keyword(s):  
Single Molecule ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Underlying Mechanism ◽  
Spintronic Devices ◽  
Spin Direction ◽  
Spin Polarized ◽  
Phthalocyanine Molecule ◽  
Filtering Effect ◽  
Spin Filtering

Spintronic devices will play a very important role in future information technology. In this study, By spin-polarized density-functional theory calculations combined with the Keldysh nonequilibrium Green’s method, the effect of the spin direction of Co atom in Co- phthalocyanine molecule in modulating spin filtering effects under external biases are investigated. Here, an individual single molecule Co-phthalocyanine is sandwiched between two infinite 8-zigzag-graphene nanoribbon electrodes. we find that the spin direction of the Co atom relative to the magnetic polarization of the left and right electrodes can improve the spin filtering effect greatly. when the polarization direction of the two electrodes is antiparallel and the polarization of Co atom in the Co-phthalocyanine molecule upward, the configuration posesses almost perfectly spin-filter effect. The underlying mechanism of the perfect spin filtering action is applied.

scholarly journals Optical probes of molecules as nano-mechanical switches

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Dean Kos ◽  
Giuliana Di Martino ◽  
Alexandra Boehmke ◽  
Bart de Nijs ◽  
Dénes Berta ◽  
...  
Keyword(s):  
Molecular Electronics ◽  
Single Molecule ◽  
Electrical Transport ◽  
Density Functional ◽  
Information Technologies ◽  
Electronic Device ◽  
Density Functional Theory Calculations ◽  
Molecular Junction ◽  
Single Molecule Level ◽  
Ultralow Energy

AbstractMolecular electronics promises a new generation of ultralow-energy information technologies, based around functional molecular junctions. Here, we report optical probing that exploits a gold nanoparticle in a plasmonic nanocavity geometry used as one terminal of a well-defined molecular junction, deposited as a self-assembled molecular monolayer on flat gold. A conductive transparent cantilever electrically contacts individual nanoparticles while maintaining optical access to the molecular junction. Optical readout of molecular structure in the junction reveals ultralow-energy switching of ∼50 zJ, from a nano-electromechanical torsion spring at the single molecule level. Real-time Raman measurements show these electronic device characteristics are directly affected by this molecular torsion, which can be explained using a simple circuit model based on junction capacitances, confirmed by density functional theory calculations. This nanomechanical degree of freedom is normally invisible and ignored in electrical transport measurements but is vital to the design and exploitation of molecules as quantum-coherent electronic nanodevices.

SPIN-FILTERING, RECTIFYING AND NEGATIVE DIFFERENTIAL RESISTANCE BEHAVIORS IN Co(dmit)2 MOLECULAR DEVICES WITH MONATOMIC (C, Fe, Au) ELECTRODES

SPIN ◽  
2014 ◽  
Vol 04 (02) ◽  
pp. 1440016
Author(s):  
SHENLANG YAN ◽  
MENGQIU LONG ◽  
XIAOJIAO ZHANG ◽  
JUN HE ◽  
HUI XU ◽  
...  
Keyword(s):  
Single Molecule ◽  
Negative Differential Resistance ◽  
Density Functional ◽  
Electrode Materials ◽  
Energy Levels ◽  
Differential Resistance ◽  
Interesting Phenomenon ◽  
Filtering Effect ◽  
Dependent Transport ◽  
Spin Filtering

Using nonequilibrium Green's functions (NEGFs) combined with the density functional theory (DFT), we study the electronic transport properties of a single molecule magnet Co ( dmit )2, which is sandwiched between two monatomic chain electrodes, and the different electrode materials carbon, iron and gold, have been considered. The results show that the electrodes play a crucial role in the spin-dependent transport of the Co ( dmit )2 molecular device, and some interesting phenomenon, such as perfect spin-filtering effect, rectifying and negative differential resistance (NDR) can be observed. We demonstrated that the magnetic Fe electrode can lead to high spin-flittering effect, and the different hybridization and alignment of energy levels between the molecule and the electrodes may be responsible for the rectification performance, and the distributions (delocalization or localization) of the frontier molecular orbitals under different bias result in the NDR behaviors. These characteristics could be used in the study of spin physics and the realization of nanospintronic devices.

scholarly journals Cross-plane transport in a single-molecule two-dimensional van der Waals heterojunction

2020 ◽  
Vol 6 (22) ◽  
pp. eaba6714 ◽  
Author(s):  
Shiqiang Zhao ◽  
Qingqing Wu ◽  
Jiuchan Pi ◽  
Junyang Liu ◽  
Jueting Zheng ◽  
...  
Keyword(s):  
Charge Transport ◽  
Single Molecule ◽  
Density Functional ◽  
Electronic Materials ◽  
2D Materials ◽  
Molecular Layer ◽  
Van Der Waals ◽  
Density Functional Theory Calculations ◽  
Two Dimensional ◽  
Guest Molecules

Two-dimensional van der Waals heterojunctions (2D-vdWHs) stacked from atomically thick 2D materials are predicted to be a diverse class of electronic materials with unique electronic properties. These properties can be further tuned by sandwiching monolayers of planar organic molecules between 2D materials to form molecular 2D-vdWHs (M-2D-vdWHs), in which electricity flows in a cross-plane way from one 2D layer to the other via a single molecular layer. Using a newly developed cross-plane break junction technique, combined with density functional theory calculations, we show that M-2D-vdWHs can be created and that cross-plane charge transport can be tuned by incorporating guest molecules. The M-2D-vdWHs exhibit distinct cross-plane charge transport signatures, which differ from those of molecules undergoing in-plane charge transport.

scholarly journals Transport properties of a three-shell icosahedral matryoshka cluster: a first-principles study

RSC Advances ◽  
2017 ◽  
Vol 7 (21) ◽  
pp. 12704-12710 ◽  
Author(s):  
Lu Zhang ◽  
Jing Huang ◽  
Weiyi Wang ◽  
Qunxiang Li ◽  
Jinlong Yang
Keyword(s):  
Transport Properties ◽  
Magnetic Moment ◽  
First Principles ◽  
Molecular Devices ◽  
Molecular Junction ◽  
First Principles Study ◽  
Cluster A ◽  
Filtering Effect ◽  
Spin Filtering

The molecular junction based on three-shell icosahedral matryoshka cluster with huge magnetic moment exhibits robust spin-filtering effect, which highlights it for promising applications in molecular devices.

scholarly journals Spin-Filtering Effects in Würtzite and Graphite-Like AlN Nanowires with Mn Impurities

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
G. A. Nemnes
Keyword(s):  
Phase Transition ◽  
Density Functional ◽  
Surface States ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Group Iii ◽  
Magnetic Nanowire ◽  
Group Iii Nitride ◽  
Basic Prerequisite ◽  
Spin Filtering

Spin transport properties of magnetic nanowire systems—atomic-sized AlN nanowires with additional Mn impurities—are investigated employingab initioconstrained spin density functional theory calculations and nonequilibrium Green’s functions formalism. The analyzed nanowire structures exhibit a stress-induced phase transition, between würtzite and graphite-like configurations. In these quasi-one dimensional systems, the surface states ensure the basic prerequisite in establishing spin and charge transfer, by reducing the relatively large bandgap of the group III nitride semiconductor. The results show in how far this phase transition affects the surface states, focusing on the consequences which appear in the spin-filtering processes.

scholarly journals Insights into the magnetic origin of CunCr (n= 9÷11) clusters: A superposition of magnetic and electronic shells

2020 ◽  
Vol 58 (1) ◽  
pp. 31
Author(s):  
Nguyen Thi Mai ◽  
Ngo Thi Lan ◽  
Nguyen Thanh Tung
Keyword(s):  
Density Functional Theory ◽  
Magnetic Moment ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Magnetic Origin

Interests in Cu-Cr sub-nanometer systems have been increasing due to the recently-found icosahedral Cu12Cr cluster as a superatomic molecule, where the 3d-Cr and 4s-Cu electrons can phenomenologically form the 18-e molecular shell (1S21P61D10) of Cu12Cr. In this report, we set out to investigate the energetically-preferred geometries and stabilities of CunCr (n = 9÷11) clusters using the density-functional-theory calculations. It is found that not all of 3d-Cr electrons involve in the formation of the cluster shell and the remaining localized ones cause the magnetic moment of the clusters, which is different from what was believed.

scholarly journals Substrate induced electronic phase transitions of CrI$$_{3}$$ based van der Waals heterostructures

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shamik Chakraborty ◽  
Abhilash Ravikumar
Keyword(s):  
Phase Transitions ◽  
Magnetic Moment ◽  
Density Functional ◽  
Van Der Waals ◽  
Density Functional Theory Calculations ◽  
Spin Orbit Coupling ◽  
Dirac Cone ◽  
Functional Theory ◽  
Electronic Phase ◽  
Principle Density Functional Theory

AbstractWe perform first principle density functional theory calculations to predict the substrate induced electronic phase transitions of CrI$$_{3}$$ 3 based 2-D heterostructures. We adsorb graphene and MoS$$_{2}$$ 2 on novel 2-D ferromagnetic semiconductor—CrI$$_{3}$$ 3 and investigate the electronic and magnetic properties of these heterostructures with and without spin orbit coupling (SOC). We find that when strained MoS$$_{2}$$ 2 is adsorbed on CrI$$_{3}$$ 3 , the spin dependent band gap which is a characteristic of CrI$$_{3}$$ 3 , ceases to remain. The bandgap of the heterostructure reduces drastically ($$\sim$$ ∼ 70%) and the heterostructure shows an indirect, spin-independent bandgap of $$\sim$$ ∼ 0.5 eV. The heterostructure remains magnetic (with and without SOC) with the magnetic moment localized primarily on CrI$$_{3}$$ 3 . Adsorption of graphene on CrI$$_{3}$$ 3 induces an electronic phase transition of the subsequent heterostructure to a ferromagnetic metal in both the spin configurations with magnetic moment localized on CrI$$_{3}$$ 3 . The SOC induced interaction opens a bandgap of $$\sim$$ ∼ 30 meV in the Dirac cone of graphene, which allows us to visualize Chern insulating states without reducing van der Waals gap.

Temperature-controlled colossal magnetoresistance and perfect spin Seebeck effect in hybrid graphene/boron nitride nanoribbons

2017 ◽  
Vol 19 (5) ◽  
pp. 4085-4092 ◽  
Author(s):  
Lin Zhu ◽  
Ruimin Li ◽  
Kailun Yao
Keyword(s):  
Boron Nitride ◽  
Density Functional ◽  
Colossal Magnetoresistance ◽  
Spin Transport ◽  
Hexagonal Boron Nitride ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Spin Seebeck Effect ◽  
Temperature Controlled ◽  
Boron Nitride Nanoribbons

Thermal spin transport properties of graphene and hexagonal boron nitride nanoribbon heterojunctions have been investigated using density functional theory calculations combined with the Keldysh nonequilibrium Green's function approach.

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