Structures, electronic properties and adsorption mechanisms of the O2Fe3N clusters

The structures, adsorption mechanisms and electronic attributes of the O2Fe3N clusters are calculated at Perdew, Burke and Ernzerhof (PBE) functional. The results show that two O atoms prefer to be located at the Fe–Fe bridge site of Fe–N molecule which form the ground-state O2Fe3N cluster, respectively. It means that O2 molecule is dissociated by Fe3N molecule. Compared to the isomer (3)–(6), it indicates that an O2 molecule is preferentially adsorbed on the top site of Fe atom which is close to N atom of the Fe3N molecule in the vertical direction. The adsorptions of Fe3N with O2 are the exothermic before endothermic reaction. All the O2Fe3N clusters possess higher kinetic activity. The average spin magnetic moments of the O2Fe3N clusters are as follows: isomer (6) [Formula: see text] isomer (1) [Formula: see text] isomer (3) [Formula: see text] isomer (5) [Formula: see text] ground-state [Formula: see text] isomer (2) [Formula: see text] isomer (4). Compared to the external charge transfer of the O2Fe3N clusters, the transfer of electrons between 4s and 3d, 4p orbitals in the same atom is significantly higher.

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Theoretical investigation of transition metals (subgroup = 8, 9, 10 and 11) substituted (MgO)9 nanotube clusters

Modern Physics Letters B ◽

10.1142/s0217984919504591 ◽

2019 ◽

Vol 33 (36) ◽

pp. 1950459 ◽

Cited By ~ 5

Author(s):

Zhen Zhao ◽

Zhi Li

Keyword(s):

Magnetic Properties ◽

Transition Metals ◽

Theoretical Investigation ◽

Ground State ◽

First Principles ◽

Hexagonal Ring ◽

Electronic And Magnetic Properties ◽

Kinetic Activity ◽

State Formula ◽

Homo And Lumo

The structures, electronic and magnetic properties of the transition metals (TMs) (subgroup = 8, 9, 10 and 11) substituted [Formula: see text] nanotube clusters have been investigated using first-principles at the PBE functional. The results show that as for the [Formula: see text] clusters, [Formula: see text] atoms and Re atoms prefer to substitute the Mg atoms which occupy the edge position of the [Formula: see text] nanotube clusters, while [Formula: see text] and [Formula: see text] atoms prefer to substitute the Mg atoms which occupy the middle hexagonal ring [Formula: see text] nanotube clusters expect for Re atoms. The [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text]O9 clusters are more stable than other TMs-substituted [Formula: see text] nanotube clusters. TM substituting significantly improves the kinetic activity of the [Formula: see text] nanotube clusters. The HOMO and LUMO states display evident hybridization between the TMs [Formula: see text] and O [Formula: see text] band states. A few [Formula: see text] orbital electrons of the TM atoms transfers to O atoms. As for the spins of the [Formula: see text] TM atoms for the ground state [Formula: see text] and [Formula: see text] (subgroup = 8, 9, 10 and 11) clusters, [Formula: see text].

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Structures, electronic and magnetic properties of transition metals-doped Mg9O9 tubular clusters

International Journal of Modern Physics B ◽

10.1142/s0217979220502112 ◽

2020 ◽

Vol 34 (21) ◽

pp. 2050211

Author(s):

Zhi Li ◽

Tao-Tao Shao ◽

Zhen Zhao

Keyword(s):

Magnetic Properties ◽

Transition Metal ◽

Ground State ◽

The Other ◽

Bridge Site ◽

Kinetic Activity ◽

Edge Site ◽

Structurally Stable ◽

Maximum Spin ◽

Cu And Zn

The structures, electronic and magnetic attributes of the transition metal (TM) doping Mg9O9 tubular clusters have been investigated using the PBE functional. The results display that the ScMg9O9 and NiMg9O9 clusters are more structurally stable than the other TMMg9O9 clusters. An Sc atom replaces the Mg atom at the edge site of the Mg9O9 clusters, which leads to the Mg atom transferring to the top of an adjacent O atom. Ni atom prefers to occupy the bridge site of the Mg–O bond at a side of the Mg9O9 clusters. VMg9O9 and FeMg9O9 display more kinetic activity than the other TMMg9O9 clusters. The TM atoms lost certain electrons except for Co, Cu and Zn. The maximum spin value of the TM atoms for the ground-state TMMg9O9 clusters occurs at Mn.

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Adsorption mechanisms and electronic and magnetic properties of oxygen on iron tetranitride

International Journal of Modern Physics B ◽

10.1142/s0217979220501738 ◽

2020 ◽

Vol 34 (19) ◽

pp. 2050173 ◽

Cited By ~ 1

Author(s):

Zhi Li ◽

Tong-Tong Shi ◽

Zhen Zhao

Keyword(s):

First Principles ◽

Electrode Materials ◽

Adsorption Process ◽

Physical Adsorption ◽

Iron Nitrides ◽

Adsorption Mechanisms ◽

Kinetic Activity ◽

Average Spin ◽

Adsorption And Dissociation ◽

Center Site

The oxide layer on iron nitrides restricts the conductivity of electrode materials. The adsorption and dissociation processes of O2 on the Fe4N have been analyzed by using first-principles. Comparing all the O2Fe4N isomers, we find that O atom prefers to locate at the center site of Fe–Fe–Fe plane which stays away from N atom. It means that O2 molecule is dissociated on the surface of Fe4N molecule. Endothermic and exothermic processes occur with the adsorption and decomposition of O2 on the surface of Fe4N. All the O2Fe4N clusters still present higher kinetic activity. For the O2Fe4N clusters, the internal electrons transfer from 4[Formula: see text] to 3[Formula: see text] and 4[Formula: see text] orbitals which are obviously more than those transfer to the other atoms. O atoms acquire less electron from nearby Fe atoms which confirms that the adsorption of O2 on Fe4N is a physical adsorption process. The average spin of the ground-state O2Fe4N clusters is 1.805 [Formula: see text]/atom.

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Fluorescence Quenching of Aminodiphenylamines with Chloromethanes

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20021154 ◽

2002 ◽

Vol 67 (8) ◽

pp. 1154-1164 ◽

Cited By ~ 2

Author(s):

Nachiappan Radha ◽

Meenakshisundaram Swaminathan

Keyword(s):

Charge Transfer ◽

Fluorescence Quenching ◽

Ground State ◽

Rate Constants ◽

Quenching Mechanism ◽

Quenching Rate ◽

Charge Transfer Interaction ◽

Electronically Excited ◽

A Charge

The fluorescence quenching of 2-aminodiphenylamine (2ADPA), 4-aminodiphenylamine (4ADPA) and 4,4'-diaminodiphenylamine (DADPA) with tetrachloromethane, chloroform and dichloromethane have been studied in hexane, dioxane, acetonitrile and methanol as solvents. The quenching rate constants for the process have also been obtained by measuring the lifetimes of the fluorophores. The quenching was found to be dynamic in all cases. For 2ADPA and 4ADPA, the quenching rate constants of CCl4 and CHCl3 depend on the viscosity, whereas in the case of CH2Cl2, kq depends on polarity. The quenching rate constants for DADPA with CCl4 are viscosity-dependent but the quenching with CHCl3 and CH2Cl2 depends on the polarity of the solvents. From the results, the quenching mechanism is explained by the formation of a non-emissive complex involving a charge-transfer interaction between the electronically excited fluorophores and ground-state chloromethanes.

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Charge Transfer Between CO22+ and Ar or Ne at Collision Energies 3-10 eV

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20030178 ◽

2003 ◽

Vol 68 (1) ◽

pp. 178-188 ◽

Cited By ~ 3

Author(s):

Libor Mrázek ◽

Ján Žabka ◽

Zdeněk Dolejšek ◽

Zdeněk Herman

Keyword(s):

Charge Transfer ◽

Excited States ◽

Ground State ◽

Scattering Method ◽

Translational Energy ◽

Centre Of Mass ◽

Energy Distributions ◽

Zener Model ◽

Beam Scattering ◽

Product Ions

The beam scattering method was used to investigate non-dissociative single-electron charge transfer between the molecular dication CO22+ and Ar or Ne at several collision energies between 3-10 eV (centre-of-mass, c.m.). Relative translational energy distributions of the product ions showed that in the reaction with Ar the CO2+ product was mainly formed in reactions of the ground state of the dication, CO22+(X3Σg-), leading to the excited states of the product CO2+(A2Πu) and CO2+(B2Σu+). In the reaction with Ne, the largest probability had the process from the reactant dication excited state CO22+(1Σg+) leading to the product ion ground state CO2+(X2Πg). Less probable were processes between the other excited states of the dication CO22+, (1∆g), (1Σu-), (3∆u), also leading to the product ion ground state CO2+(X2Πg). Using the Landau-Zener model of the reaction window, relative populations of the ground and excited states of the dication CO22+ in the reactant beam were roughly estimated as (X3Σg):(1∆g):(1Σg+):(1Σu-):(3∆u) = 1.0:0.6:0.5:0.25:0.25.

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Revealing noncollinear magnetic ordering at the atomic scale via XMCD

Scientific Reports ◽

10.1038/s41598-021-82518-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Fridtjof Kielgast ◽

Ivan Baev ◽

Torben Beeck ◽

Federico Pressacco ◽

Michael Martins

Keyword(s):

Ground State ◽

Magnetic Circular Dichroism ◽

Magnetic Moments ◽

Magnetic Ordering ◽

Atomic Scale ◽

Angle Of Incidence ◽

X Ray ◽

First Time ◽

X Ray Absorption ◽

Magnetic Sublattices

AbstractMass-selected V and Fe monomers, as well as the heterodimer $${\text{Fe}}_1{\text{V}}_1$$ Fe 1 V 1 , were deposited on a Cu(001) surface. Their electronic and magnetic properties were investigated via X-ray absorption (XAS) and X-ray magnetic circular dichroism (XMCD) spectroscopy. Anisotropies in the magnetic moments of the deposited species could be examined by means of angle resolving XMCD, i.e. changing the X-ray angle of incidence. A weak adatom-substrate-coupling was found for both elements and, using group theoretical arguments, the ground state symmetries of the adatoms were determined. For the dimer, a switching from antiparallel to parallel orientation of the respective magnetic moments was observed. We show that this is due to the existence of a noncollinear spin-flop phase in the deposited dimers, which could be observed for the first time in such a small system. Making use of the two magnetic sublattices model, we were able to find the relative orientations for the dimer magnetic moments for different incidence angles.

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