Articoli di riviste: "Single atom electronics"

1

De Franceschi, Silvano, e Leo Kouwenhoven. "Electronics and the single atom". Nature 417, n. 6890 (giugno 2002): 701–2. http://dx.doi.org/10.1038/417701a.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

2

Fuhrer, Michael S., Chun Ning Lau e Allan H. MacDonald. "Graphene: Materially Better Carbon". MRS Bulletin 35, n. 4 (aprile 2010): 289–95. http://dx.doi.org/10.1557/mrs2010.551.

Testo completo

Abstract (sommario):

AbstractGraphene, a single atom–thick plane of carbon atoms arranged in a honeycomb lattice, has captivated the attention of physicists, materials scientists, and engineers alike over the five years following its experimental isolation. Graphene is a fundamentally new type of electronic material whose electrons are strictly confined to a two-dimensional plane and exhibit properties akin to those of ultrarelativistic particles. Graphene's two-dimensional form suggests compatibility with conventional wafer processing technology. Extraordinary physical properties, including exceedingly high charge carrier mobility, current-carrying capacity, mechanical strength, and thermal conductivity, make it an enticing candidate for new electronic technologies both within and beyond complementary metal oxide semiconductors (CMOS). Immediate graphene applications include high-speed analog electronics and highly conductive, flexible, transparent thin films for displays and optoelectronics. Currently, much graphene research is focused on generating and tuning a bandgap and on novel device structures that exploit graphene's extraordinary electrical, optical, and mechanical properties.

Gli stili APA, Harvard, Vancouver, ISO e altri

3

Obermair, Ch, F. Q. Xie e Th Schimmel. "The Single-Atom Transistor: perspectives for quantum electronics on the atomic-scale". Europhysics News 41, n. 4 (luglio 2010): 25–28. http://dx.doi.org/10.1051/epn/2010403.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

4

Weber, B., S. Mahapatra, H. Ryu, S. Lee, A. Fuhrer, T. C. G. Reusch, D. L. Thompson et al. "Ohm’s Law Survives to the Atomic Scale". Science 335, n. 6064 (5 gennaio 2012): 64–67. http://dx.doi.org/10.1126/science.1214319.

Testo completo

Abstract (sommario):

As silicon electronics approaches the atomic scale, interconnects and circuitry become comparable in size to the active device components. Maintaining low electrical resistivity at this scale is challenging because of the presence of conﬁning surfaces and interfaces. We report on the fabrication of wires in silicon—only one atom tall and four atoms wide—with exceptionally low resistivity (~0.3 milliohm-centimeters) and the current-carrying capabilities of copper. By embedding phosphorus atoms within a silicon crystal with an average spacing of less than 1 nanometer, we achieved a diameter-independent resistivity, which demonstrates ohmic scaling to the atomic limit. Atomistic tight-binding calculations conﬁrm the metallicity of these atomic-scale wires, which pave the way for single-atom device architectures for both classical and quantum information processing.

Gli stili APA, Harvard, Vancouver, ISO e altri

5

Hu, Xielong, e Fanyan Meng. "First-Principle Study on the Interaction between Fe and Trivacancy in Graphene". Journal of Nanomaterials 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/2672816.

Testo completo

Abstract (sommario):

Ab initio calculations using density functional theory (DFT) have been performed in order to explore structure and energy gap opening of graphene with bridged-trivacancy and single adsorbed with Fe atom. Compared to the previous reconstructed trivacancy adsorbed with Fe atom with the energy gap of 0.10 eV, one interesting structure for the Fe-doped bridged-trivacancy complex has been identified, with one Fe atom above the graphene plane, and possesses energy gap with the value of 0.32 eV in the bridged circumstance. The band gap can be explained by the decrease of the free electrons. These results provide insights to engineer graphene’s properties through defect addition and manipulation for industrial semiconductor applications such as the photocatalytic technology and graphene based electronics.

Gli stili APA, Harvard, Vancouver, ISO e altri

6

Liang, Zefen, Tianxiang He, Junpeng An, Hongtao Xue, Fuling Tang e Ding Fan. "Coupling effect and charge redistribution of cyclo[18]carbons and cyclocarbon oxides on NaCl surface". International Journal of Modern Physics B 34, n. 13 (20 maggio 2020): 2050138. http://dx.doi.org/10.1142/s0217979220501386.

Testo completo

Abstract (sommario):

The electronic structure, energy barrier and charge redistribution of cyclo[18]carbon and cyclocarbon oxides [Formula: see text], [Formula: see text], [Formula: see text] on NaCl(001) surface were computationally studied by using MOPAC. The HOMO electronics are mainly distributed at the inner and outer circumferential half circle of the cyclo[18]carbon along triple C–C bonds. However, the LUMO electronics are distributed at above and below surfaces of the cyclo[18]carbon circle along single C–C bonds. The energy barrier is different along different direction. The energy barrier of cyclo[18]carbon on the NaCl surface is the smallest (0.23 eV/per atom). When the cyclo[18]carbon and cyclo[18]carbon oxides molecular are put on the NaCl surface, they show different amounts of positive charge, no longer neutral.

Gli stili APA, Harvard, Vancouver, ISO e altri

7

Nies, Cara-Lena, e Michael Nolan. "DFT calculations of the structure and stability of copper clusters on MoS2". Beilstein Journal of Nanotechnology 11 (26 febbraio 2020): 391–406. http://dx.doi.org/10.3762/bjnano.11.30.

Testo completo

Abstract (sommario):

Layered materials, such as MoS2, are being intensely studied due to their interesting properties and wide variety of potential applications. These materials are also interesting as supports for low-dimensional metals for catalysis, while recent work has shown increased interest in using 2D materials in the electronics industry as a Cu diffusion barrier in semiconductor device interconnects. The interaction between different metal structures and MoS2 monolayers is therefore of significant importance and first-principles simulations can probe aspects of this interaction not easily accessible to experiment. Previous theoretical studies have focused particularly on the adsorption of a range of metallic elements, including first-row transition metals, as well as Ag and Au. However, most studies have examined single-atom adsorption or adsorbed nanoparticles of noble metals. This means there is a knowledge gap in terms of thin film nucleation on 2D materials. To begin addressing this issue, we present in this paper a first-principles density functional theory (DFT) study of the adsorption of small Cu n (n = 1–4) structures on 2D MoS2 as a model system. We find on a perfect MoS2 monolayer that a single Cu atom prefers an adsorption site above the Mo atom. With increasing nanocluster size the nanocluster binds more strongly when Cu atoms adsorb atop the S atoms. Stability is driven by the number of Cu–Cu interactions and the distance between adsorption sites, with no obvious preference towards 2D or 3D structures. The introduction of a single S vacancy in the monolayer enhances the copper binding energy, although some Cu n nanoclusters are actually unstable. The effect of the vacancy is localised around the vacancy site. Finally, on both the pristine and the defective MoS2 monolayer, the density-of-states analysis shows that the adsorption of Cu introduces new electronic states as a result of partial Cu oxidation, but the metallic character of Cu nanoclusters is preserved.

Gli stili APA, Harvard, Vancouver, ISO e altri

8

Zaporotskova, Irina, Olesia Kakorina e Igor Kakorin. "Modification of Pyrolyzed Polyacrylonitrile with Silver Atoms". NBI Technologies, n. 2 (dicembre 2020): 32–41. http://dx.doi.org/10.15688/nbit.jvolsu.2020.2.6.

Testo completo

Abstract (sommario):

Recently, the search for new materials for nanoelectronics has attracted the interest of scientists. New materials, which are metal-polymer nanocomposites, can be used in modern electronics. The paper presents the possibility and mechanisms for the formation of a metal composite based on single-layer and two-layer pyrolyzed polyacrylonitrile when interacting with silver atoms. The results of the silver atom adsorption on the polymer surface are described, the possibility of filling the interlayer space with metal atoms is shown, and geometric and electron-energy characteristics are established. Theoretical calculations were performed using a molecular cluster model using a non-empirical method in the STO basis. The structure and electron-energy state of a metal-carbon nanocomposite based on pyrolyzed polyacrylonitrile with silver atoms are studied. It was found that the silver atom is adsorbed on the surface of PPAN, and the adsorption process is almost independent of the selected adsorption center. The introduction of metal atoms into the interplanar space of PPAN causes the initially planar monolayers of PPAN to bend, while the structure retains its stability. It was found that the presence of metal atoms in the PPAN structure causes a change in the band gap, which leads to a change in the conductive properties of the resulting nanocomposite.

Gli stili APA, Harvard, Vancouver, ISO e altri

9

Surmacz, Karolina, e Paweł Chmielarz. "Low Ppm Atom Transfer Radical Polymerization in (Mini)Emulsion Systems". Materials 13, n. 7 (6 aprile 2020): 1717. http://dx.doi.org/10.3390/ma13071717.

Testo completo

Abstract (sommario):

In the last decade, unceasing interest in atom transfer radical polymerization (ATRP) has been noted, especially in aqueous dispersion systems. Emulsion or miniemulsion is a preferred environment for industrial polymerization due to easier heat dissipation and lower production costs associated with the use of water as a dispersant. The main purpose of this review is to summarize ATRP methods used in emulsion media with different variants of initiating systems. A comparison of a dual over single catalytic approache by interfacial and ion pair catalysis is presented. In addition, future development directions for these methods are suggested for better use in biomedical and electronics industries.

Gli stili APA, Harvard, Vancouver, ISO e altri

10

Kusuma, Theresia Sita, Emdeniz e Syukri Arief. "PENGARUH LOGAM Li PADA ADSORPSI ATOM-ATOM H OLEH PERMUKAAN GRAFENA PLANAR". Jurnal Riset Kimia 1, n. 1 (11 febbraio 2015): 71. http://dx.doi.org/10.25077/jrk.v1i1.91.

Testo completo

Abstract (sommario):

ABSTRACT Graphene has future prospect for electronics. By adding some substituents this material can be tuned to behave like a metal or semiconductor. In this investigation, a planar single layer of modified graphene, C24H12-mLim (m = 0, 3, 6, and 12) consisted of seven six-member rings was used to adsorb the oncoming hydrogen (perpendicular to the surface, was defined as Had). A planar twolayer graphene C48H24 (7+7) was also included. To determine the adsorption models and the Had couverage, a semiempiris Calzaferri program, works on pentium 4 windows 98, was used to optimize nHad (n = 1, 2, and 3) that reached the surfaces. The heat of Had adsorption and the band gap of the surfaces were also computed. Results of these computations showed that: (1) the adsorption process was endothermic and Li reduced the heat of Had adsorption on the surfaces. (2) Li reduced the band gap of the surfaces, so C24H12 was a semiconductor but C24Li12 a conductor. (3) The adsorbed nHad always lowered the band gap of the surfaces, in exception of C24Li12 could be lower or higher. (4) Each atom on the surfaces, in exception hydrogen, might adsorb nHad formed tilted (with C) and lying down (with Li) surface complexes, and for C24H6Li6 an asymmetric twofold complex was also observed. (5) However, the Had couverage was low, some Had formed H2 and this was not observed on C24H6Li6. (6) The C48H24 kept an H2 molecule between layers. Thus, a new material C24H6Li6 which had two adsorption models, might increase the Had couverage, but had lower conductivity than that of C24H12. On the other hand, it is necessary to study in more details the hydrogen storage between graphene layers. Key words: graphene, adsorption, substituent

Gli stili APA, Harvard, Vancouver, ISO e altri

11

Das, Satyendra K., Rashmohan Guin, Debasish Banerjee, Karl Johnston, Parnika Das, Tilman Butz, Vitor S. Amaral, Joao G. Correia e Marcelo B. Barbosa. "Perturbed Angular Correlation Study of the Static and Dynamic Aspects of Cadmium and Mercury Atoms Inside and Attached to a C60 Fullerene Cage". Zeitschrift für Naturforschung A 69, n. 10-11 (1 novembre 2014): 611–18. http://dx.doi.org/10.5560/zna.2014-0055.

Testo completo

Abstract (sommario):

Abstract30 keV 111mCd and 50 keV 199mHg beams from ISOLDE were used to implant on preformed targets of C60 with a thickness of 1 mg cm-2. Endofullerene compounds, viz. 111mCd@C60 and 199mHg@C60 formed during implantation were separated by filtration through micropore filter paper followed by solvent extraction. Dried samples of the endofullerene compounds were counted for the time differential perturbed angular correlation (TDPAC) measurement using the coincidence of the 151 - 245 keV cascade of 111mCd and the 374 - 158 keV cascade of 199mHg on a six LaBr3(Ce) detector system coupled with digital electronics. The results for 111mCd@C60 indicate a single static component (27%) and a fast relaxing component (73%), the latter implying that the cadmium atom moves rapidly inside the cage at room temperature. The quadrupole interaction frequency and asymmetry parameter of the cadmium atom occupying the static site in C60 are wQ=8.21(36) Mrad s-1 and η = 0.41(9), respectively. The fast relaxation constant is 0.0031(4) ns-1. Similarly, mercury atoms also exhibit a single static and a fast component. The static site has a quadrupole frequency wQ=283.0(12.4) Mrad s-1 and η =0 with a fraction of 30%. The fast relaxation constant is 0.045(8) ns-1 with a fraction of 70%, very similar to that of cadmium.

Gli stili APA, Harvard, Vancouver, ISO e altri

12

Hong, Jinhua, Chuanhong Jin, Jun Yuan e Ze Zhang. "Atomic Defects in Two-Dimensional Materials: From Single-Atom Spectroscopy to Functionalities in Opto-/Electronics, Nanomagnetism, and Catalysis". Advanced Materials 29, n. 14 (10 marzo 2017): 1606434. http://dx.doi.org/10.1002/adma.201606434.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

13

Ortega, Vilhena, Zotti, Díez-Pérez, Cuevas e Pérez. "Tuning Structure and Dynamics of Blue Copper Azurin Junctions via Single Amino-Acid Mutations". Biomolecules 9, n. 10 (15 ottobre 2019): 611. http://dx.doi.org/10.3390/biom9100611.

Testo completo

Abstract (sommario):

In the growing field of biomolecular electronics, blue-copper Azurin stands out as one of the most widely studied protein in single-molecule contacts. Interestingly, despite the paramount importance of the structure/dynamics of molecular contacts in their transport properties, these factors remain largely unexplored from the theoretical point of view in the context of single Azurin junctions. Here we address this issue using all-atom Molecular Dynamics (MD) of Pseudomonas Aeruginosa Azurin adsorbed to a Au(111) substrate. In particular, we focus on the structure and dynamics of the free/adsorbed protein and how these properties are altered upon single-point mutations. The results revealed that wild-type Azurin adsorbs on Au(111) along two well defined configurations: one tethered via cysteine groups and the other via the hydrophobic pocket surrounding the Cu 2 + . Surprisingly, our simulations revealed that single amino-acid mutations gave rise to a quenching of protein vibrations ultimately resulting in its overall stiffening. Given the role of amino-acid vibrations and reorientation in the dehydration process at the protein-water-substrate interface, we suggest that this might have an effect on the adsorption process of the mutant, giving rise to new adsorption configurations.

Gli stili APA, Harvard, Vancouver, ISO e altri

14

Willke, Philip, Yujeong Bae, Kai Yang, Jose L. Lado, Alejandro Ferrón, Taeyoung Choi, Arzhang Ardavan, Joaquín Fernández-Rossier, Andreas J. Heinrich e Christopher P. Lutz. "Hyperfine interaction of individual atoms on a surface". Science 362, n. 6412 (18 ottobre 2018): 336–39. http://dx.doi.org/10.1126/science.aat7047.

Testo completo

Abstract (sommario):

Taking advantage of nuclear spins for electronic structure analysis, magnetic resonance imaging, and quantum devices hinges on knowledge and control of the surrounding atomic-scale environment. We measured and manipulated the hyperfine interaction of individual iron and titanium atoms placed on a magnesium oxide surface by using spin-polarized scanning tunneling microscopy in combination with single-atom electron spin resonance. Using atom manipulation to move single atoms, we found that the hyperfine interaction strongly depended on the binding configuration of the atom. We could extract atom- and position-dependent information about the electronic ground state, the state mixing with neighboring atoms, and properties of the nuclear spin. Thus, the hyperfine spectrum becomes a powerful probe of the chemical environment of individual atoms and nanostructures.

Gli stili APA, Harvard, Vancouver, ISO e altri

15

Sk, Mahasin Alam, e Sergei Manzhos. "Sodium Interaction with Disodium Terephthalate Molecule: an Ab Initio Study". MRS Advances 1, n. 53 (2016): 3579–84. http://dx.doi.org/10.1557/adv.2016.452.

Testo completo

Abstract (sommario):

ABSTRACTDisodium terephthalate (Na2TP), which is a disodium salt of terephthalic acid, is very promising organic electrode material for Na-ion batteries. We present an ab initio study of Na binding mechanism with Na2TP molecule. Specially, we provide the interaction energy of Na atom(s), effect of Na concentration on interaction energy, electronic properties of clean and Na attached Na2TP, and Na binding mechanism with Na2TP. We show that up to eight Na atoms can be attached to a single Na2TP molecule. The interaction energy of Na atoms varies from -0.79 to -0.66 eV with attachment of one to eight Na atoms. The adsorbed Na atom interacts with O atoms of carboxylate group and Na atoms of the salt molecule. The interaction between adsorbed Na and C atoms of the molecule is found to be not important for Na bindings. Attachment of a single Na atom generates a singly occupied orbital which becomes doubly occupied with attachment of second Na atoms. Attachment of more than two Na atoms leads to electron occupation of bonding orbitals formed between Na atoms and the carboxylate groups.

Gli stili APA, Harvard, Vancouver, ISO e altri

16

MacDougall, Preston J., e Richard F. W. Bader. "Atomic properties and the reactivity of carbenes". Canadian Journal of Chemistry 64, n. 8 (1 agosto 1986): 1496–508. http://dx.doi.org/10.1139/v86-246.

Testo completo

Abstract (sommario):

The properties of the atoms in a number of substituted carbenes and silylene provide an understanding of the relative stabilities of their lowest lying singlet and triplet states and of their differing chemical reactivities. The theory of atoms in molecules defines all of an atom's properties, including its energy. In this research one finds that the methylenic carbon or silicon atom is energetically most stable in the triplet state of each system, while the ligands are most stable in the corresponding singlet state. It is also found that the average electron populations of the carbon and silicon atoms are largest in the triplet states. In systems where the carbon or silicon atom bears a net positive charge, as found in CHNH2, CF2, and SiH2, the excess in the transfer of charge to the more electronegative ligands in the singlet states stabilizes the ligands more than it destabilizes the central atom. These systems have singlet ground states. The relative susceptibility of singlet and triplet carbenes to electrophilic and nucleophilic attack is determined by the properties of the Laplacian of the charge distribution. This quantity assimilates the model of localized electrons in terms of local concentrations of electronic charge. It also determines regions from which electronic charge is locally depleted. These regions are found to coincide with those where the lowest-lying vacant orbital is concentrated.

Gli stili APA, Harvard, Vancouver, ISO e altri

17

Neupane, Hari Krishna, e Narayan Prasad Adhikari. "Structural, Electronic and Magnetic Properties of Defected Water Adsorbed Single-Layer MoS2". Journal of Institute of Science and Technology 26, n. 1 (17 giugno 2021): 43–50. http://dx.doi.org/10.3126/jist.v26i1.37817.

Testo completo

Abstract (sommario):

Water adsorbed in MoS2 (wad-MoS2), 1S atom vacancy defect in wad-MoS2 (1S-wad-MoS2), 2S atoms vacancy defects in wad-MoS2 (2S-wad-MoS2), and 1Mo atom vacancy defect in wad-MoS2 (Mo-wad-MoS2) materials were constructed, and their structural, electronic, and magnetic properties were studied by spin-polarized density functional theory (DFT) based first-principles calculations. The wad-MoS2, 1S-wad-MoS2, 2S-wad-MoS2, and Mo-wad-MoS2 materials were found stable. From band structure calculations, wad-MoS2, 1S-wad-MoS2 and 2S-wad-MoS2 materials open energy bandgap of values 1.19 eV, 0.65 eV and 0.38 eV respectively. Also, it was found that the conductivity strength of the material increases with an increase in the concentration of S atom vacancy defects in the structure. On the other hand, the Mo-wad-MoS2 material has metallic properties because energy bands of electrons crossed the Fermi energy level in the band structure. For the investigation of magnetic properties, the density of states (DoS) and partial density of states (PDoS) calculations were used and found that wad-MoS2, 1S-wad-MoS2, and 2S-wad-MoS2 are non-magnetic materials, while Mo-wad-MoS2 is a magnetic material. The total magnetic moment of Mo-wad-MoS2 has a value of 2.66 µB/cell, due to the arrangement of unpaired up-spin and down-spin of electrons in 3s & 3p orbitals of S atoms; and 4p, 4d & 5s orbitals of Mo atoms in the material.

Gli stili APA, Harvard, Vancouver, ISO e altri

18

Ding, Xun-Lei, Heng-Lu Liao, Yan Zhang, Yi-Ming Chen, Dan Wang, Ya-Ya Wang e Hua-Yong Zhang. "Geometric and electronic properties of gold clusters doped with a single oxygen atom". Physical Chemistry Chemical Physics 18, n. 41 (2016): 28960–72. http://dx.doi.org/10.1039/c6cp05595h.

Testo completo

Abstract (sommario):

A systematic theoretical study on single oxygen atom doped gold clusters showed that a single oxygen atom can be adsorbed on various sites of gold surfaces, and obtain nearly one electron from gold atoms.

Gli stili APA, Harvard, Vancouver, ISO e altri

19

Chen, Li Qun, e Zheng Chen Qiu. "The Effect of a Light Impurity on the Electronic Structure of Dislocations in NiAl". Defect and Diffusion Forum 318 (luglio 2011): 23–32. http://dx.doi.org/10.4028/www.scientific.net/ddf.318.23.

Testo completo

Abstract (sommario):

The effect of light impurities (C, N) upon the electronic structure of the [100](010) edge dislocation core in NiAl single crystals is investigated by using the Dmol and the discrete variational method within the framework of density functional theory. The impurity segregation energy, interatomic energy and charge distribution are calculated, and the effects of impurity atoms upon the dislocation motion are discussed. The energy analysis shows that both C and N atoms can stabilize the [100](010) edge dislocation core, and prefer to occupy the interstitial site in the Center-Ni dislocation core. Meanwhile, the impurity atoms can form strong bonding states with their neighboring host atoms via hybridization between the 2p orbitals of the impurity atom and the 3d4s4p orbitals of the host Ni atoms; as well as between the 2p orbitals of the impurity atom and the 3s3p orbitals of the host Al atoms. The strong interaction between impurity atom and host atoms in the dislocation core may improve the strength of NiAl single crystals.

Gli stili APA, Harvard, Vancouver, ISO e altri

20

Zaporotskova, Irina V., Daniel P. Radchenko, Lev V. Kozhitov, Pavel A. Zaporotskov e Alena V. Popkova. "Theoretical study of metal composite based on pyrolyzed polyacrylonitrile monolayer containing Fe-Co, Ni-Co and Fe-Ni metal atom pairs and silicon amorphizing admixture". Modern Electronic Materials 6, n. 3 (30 settembre 2020): 95–99. http://dx.doi.org/10.3897/j.moem.6.3.63308.

Testo completo

Abstract (sommario):

An urgent problem of radio engineering and radioelectronics nowadays is the synthesis of composite materials with preset parameters that can be used as electronics engineering materials. Of special interest are MW range wide-band electromagnetic radiation absorbers. Special attention is paid to materials on the basis of ferromagnetic metals that are capable of effectively absorbing and reflecting incident waves and having a clear nanostructure. Development of nanocapsulated metals will allow controlling the parameters of newly designed materials. This is achieved with the use of polymer matrices, e.g. pyrolyzed polyacrylonitrile (PPAN). This work is a theoretical study of a PPAN monolayer model containing pairs of transition metal atoms iron, nickel and cobalt which possess ferromagnetic properties, in Fe-Co, Ni-Co and Fe-Ni combinations, with silicon amorphizing admixture. We studied the geometrical structure of the metal composite systems which are modeled as PPAN molecular clusters the centers of which are voided of six matrix material atoms, the resultant defects (the so-called pores) being filled with pairs of the metal atoms being studied. The metal containing monolayer proved to be distorted in comparison with the initially planar PPAN monolayer. We plotted single-electron spectra of the composite nanosystems and characterized their band gaps. The presence of metal atoms reduces the band gap of a metal composite as compared with pure PPAN. We determined the charges of the metals and found electron density transfer from metal atoms to their adjacent PPAN monolayer atoms. We calculated the average bond energy of the test metal composite systems and proved them to be stable. The studies involved the use of the density functional theory (DFT) method with the B3LYP functional and the 6-31G(d) basis.

Gli stili APA, Harvard, Vancouver, ISO e altri

21

Ganadu, Maria Luisa, Francesco Demartin, Angelo Panzanelli, Ennio Zangrando, Massimiliano Peana, Serenella Medici e Maria Antonietta Zoroddu. "Gold Clusters: From the Dispute on a Gold Chair to the Golden Future of Nanostructures". Molecules 26, n. 16 (19 agosto 2021): 5014. http://dx.doi.org/10.3390/molecules26165014.

Testo completo

Abstract (sommario):

The present work opens with an acknowledgement to the research activity performed by Luciana Naldini while affiliated at the Università degli Studi di Sassari (Italy), in particular towards gold complexes and clusters, as a tribute to her outstanding figure in a time and a society where being a woman in science was rather difficult, hoping her achievements could be of inspiration to young female chemists in pursuing their careers against the many hurdles they may encounter. Naldini’s findings will be a key to introduce the most recent results in this field, showing how the chemistry of gold compounds has changed throughout the years, to reach levels of complexity and elegance that were once unimagined. The study of gold complexes and clusters with various phosphine ligands was Naldini’s main field of research because of the potential application of these species in diverse research areas including electronics, catalysis, and medicine. As the conclusion of a vital period of study, here we report Naldini’s last results on a hexanuclear cationic gold cluster, [(PPh3)6Au6(OH)2]2+, having a chair conformation, and on the assumption, supported by experimental data, that it comprises two hydroxyl groups. This contribution, within the fascinating field of inorganic chemistry, provides the intuition of how a simple electron counting may lead to predictable species of yet unknown molecular architectures and formulation, nowadays suggesting interesting opportunities to tune the electronic structures of similar and higher nuclearity species thanks to new spectroscopic and analytical approaches and software facilities. After several decades since Naldini’s exceptional work, the chemistry of the gold cluster has reached a considerable degree of complexity, dealing with new, single-atom precise, materials possessing interesting physico-chemical properties, such as luminescence, chirality, or paramagnetic behavior. Here we will describe some of the most significant contributions.

Gli stili APA, Harvard, Vancouver, ISO e altri

22

Pamungkas, Mauludi Ariesto, Vinsa Kharisma Rofiqo Sari, Irwansyah, Setiawan Ade Putra, Abdurrouf e Muhammad Nurhuda. "Tuning Electronic Structure and Magnetic Properties of Flat Stanene by Hydrogenation and Al/P Doping: A First Principle DFT Study". Coatings 11, n. 1 (5 gennaio 2021): 47. http://dx.doi.org/10.3390/coatings11010047.

Testo completo

Abstract (sommario):

A Stanene, is a two-dimensional material composed of tin atoms arranged in a single hexagonal layer, in a manner similar to graphene. First principle studies based on density functional theory were performed to investigate the effects of hydrogenation and Al/P doping on electronic structure and magnetic properties of stanene. Hydrogenation opens the bandgap of stanene and changes it from nonmagnetic to the ferromagnetic material through H 1s states and Sn 5p states hybridization. Al/P atom at hollow site prevent electrons of adjacent Sn atoms to connect so that inducing unpaired electrons. The combination of hydrogenation and Al/P doping increases its magnetization. The sequence based on its magnetic moment from small to large is as follows: pure stanene, Al-doped stanene, P-doped stanene, hydrogenated stanene, Al-doped hydrogenated stanene, and P-doped hydrogenated stanene. The controllable transformation from nonmagnetic metallic to a magnetic semiconductor is a key requirement for materials to be used as spintronic materials. Thus, these results may shed light on designing the stanene-based electronic and spintronics materials.

Gli stili APA, Harvard, Vancouver, ISO e altri

23

Tabe, Michiharu, Daniel Moraru, Arief Udhiarto, Sakito Miki, Miftahul Anwar, Yuya Kawai e Takeshi Mizuno. "Si-Based Single-Dopant Atom Devices". Advanced Materials Research 222 (aprile 2011): 205–8. http://dx.doi.org/10.4028/www.scientific.net/amr.222.205.

Testo completo

Abstract (sommario):

We have recently proposed and demonstrated a new device concept, “Si-based single-dopant atom device”, consisting of only one or a few dopant atoms in the channel of Si field-effect transistors. The device characteristics are determined by a dopant, which is mediating electron or hole transport between source and drain electrodes. In this paper, our recent results on electronic and photonic applications are introduced. Furthermore, single-dopant images obtained by a scanning probe microscope are also presented.

Gli stili APA, Harvard, Vancouver, ISO e altri

24

Wang, Bao Zhu, Sheng Tang, Tong Wei, Jie Ren e Min Wang. "First-Principles Study of 3D Transition Metal Doped Single-Layer Graphene". Materials Science Forum 984 (aprile 2020): 82–87. http://dx.doi.org/10.4028/www.scientific.net/msf.984.82.

Testo completo

Abstract (sommario):

The electronic structure and magnetic properties of C atoms in Co, Ni-substituted graphene single-layers were studied by first-principles calculation method based on density functional theory. The study found that the pure graphene single-layer is an insulator, does not have magnetism, and we found that the doping of Co and Ni atoms alone does not make the system magnetic. Both Co and Ni atoms are capable of generating impurity levels in the graphene single-layer system. The impurity level of Co atom doping is 0.75 eV below the Fermi level, and the impurity level of Ni atom doping is 0.4 eV above the Fermi level. Studies on the coupling doping of Co and Ni atoms show that two different distance Co atoms or Ni atoms in the graphene single-layer are not always ferromagnetically coupled, and a stable magnetic ground state cannot be obtained. It can produce different magnetic ground states by controlling different doping distances, thus we provide one new way to control the spin properties.

Gli stili APA, Harvard, Vancouver, ISO e altri

25

Trinh, Lang Hoang, Tao Van Chau, Chien Hoang Le, Hong Thi Yen Huynh e Tram Ngoc Huynh. "Positron annihilation rate in single atom with slater type orbital approximation". Science and Technology Development Journal 16, n. 4 (31 dicembre 2013): 43–51. http://dx.doi.org/10.32508/stdj.v16i4.1595.

Testo completo

Abstract (sommario):

A theoretical approximation for the structure of many-positron and manyelectron atoms in bound states is presented. The purpose of this theory is to permit the calculation of positron lifetimes from annihilation enhancement factor which is directly estimated by pair correlation function for each element atom, but not analytical form of correlation functions which depend upon homogeneous electron gas Monte– Carlo simulation data. We therefore used a modified orbital approximation for the electrons and positron. The orbital modification consisting of explicit electronpositron and electron-electron correlation in each elec-tronic orbital was used for the electrons and positron wave functions. The kinetic energies of the electrons and positron were treated on the same footing, and the Born-Oppenheimer approximation was applied to the nuclei. In this paper we treated only those systems for the valance electrons in the real spatial coordinate of the atom or molecule. The complex of many-particle problem was solved by the Schrongdinger of one particle equation which is derived by Kohn–Sham approximation and single particle wave function of Slater type orbital. As a result of this model, the positron annihilation rate and lifetime in some atoms, Ti, Zn and Zr, were calculated.

Gli stili APA, Harvard, Vancouver, ISO e altri

26

GARG, ISHA, KEYA DHARAMVIR, V. K. JINDAL e HITESH SHARMA. "A FIRST-PRINCIPLE INVESTIGATION OF BORON- AND NITROGEN-DOPED HETEROFULLERENES". International Journal of Nanoscience 10, n. 01n02 (febbraio 2011): 29–33. http://dx.doi.org/10.1142/s0219581x11007430.

Testo completo

Abstract (sommario):

A systematic study of structural, electronic and vibrational properties of boron- and nitrogen-doped heterofullerenes has been performed. N and B doping lead to the structural deformation, and the dopant has a tendency to occupy a single position in a pentagon and two positions in a hexagon which are not adjacent. B -substitution produces clusters of greater thermodynamic stability than N substitution. The C–N and C–B bond lengths lie in the range of 1.40–1.44 Å and 1.53–1.57 Å for hexagon–hexagon (6, 6) and 1.39–1.46 Å and 1.55–1.60 Å at pentagon–hexagon (5, 6) interfaces, respectively. The Mulliken charge analysis shows a charge transfer of -0.30 to -0.45 electrons from N to C atoms; B atom act as electron acceptors with charge gain ranging between -0.59 to -0.70 electrons. N - and B -doping in fullerene molecules present an interesting way to alter electronic and chemical properties of the C 60 molecule for useful device applications.

Gli stili APA, Harvard, Vancouver, ISO e altri

27

Wu, Ai Qing, Qing Gong Song e Li Yang. "First-Principles Study on Al or/and P Doped SiC Nanotubes". Advanced Materials Research 510 (aprile 2012): 747–52. http://dx.doi.org/10.4028/www.scientific.net/amr.510.747.

Testo completo

Abstract (sommario):

The stability and electronic structures of Al or/and P doped single-walled SiC nanotubes (SWSiCNTs) are investigated by the first-principles theory. It is found that the ones with P atom located at Si site are most energetically favorable both for armchair and zigzag SWSiCNTs, which means that P atom is prone to substitute Si atom. In the same time, we found that the formation energy of Al substituting Si atom is lower than that of Al substituting C atom. The energetic disadvantages of P or Al atom located at C site in SWSiCNTs may be due to the obviously structural distortion in view of that the Al and P atoms are much bigger than C atom. The SWSiCNTs can be routinely modified ranging fromp-type semiconductor ton-type by Al and P substitution doping. These results are expected to give valuable information in building nanoscale electronic devices.

Gli stili APA, Harvard, Vancouver, ISO e altri

28

Ren, Fei, Mengli Yao, Min Li e Hui Wang. "Tailoring the Structural and Electronic Properties of Graphene through Ion Implantation". Materials 14, n. 17 (5 settembre 2021): 5080. http://dx.doi.org/10.3390/ma14175080.

Testo completo

Abstract (sommario):

Ion implantation is a superior post-synthesis doping technique to tailor the structural properties of materials. Via density functional theory (DFT) calculation and ab-initio molecular dynamics simulations (AIMD) based on stochastic boundary conditions, we systematically investigate the implantation of low energy elements Ga/Ge/As into graphene as well as the electronic, optoelectronic and transport properties. It is found that a single incident Ga, Ge or As atom can substitute a carbon atom of graphene lattice due to the head-on collision as their initial kinetic energies lie in the ranges of 25–26 eV/atom, 22–33 eV/atom and 19–42 eV/atom, respectively. Owing to the different chemical interactions between incident atom and graphene lattice, Ge and As atoms have a wide kinetic energy window for implantation, while Ga is not. Moreover, implantation of Ga/Ge/As into graphene opens up a concentration-dependent bandgap from ~0.1 to ~0.6 eV, enhancing the green and blue light adsorption through optical analysis. Furthermore, the carrier mobility of ion-implanted graphene is lower than pristine graphene; however, it is still almost one order of magnitude higher than silicon semiconductors. These results provide useful guidance for the fabrication of electronic and optoelectronic devices of single-atom-thick two-dimensional materials through the ion implantation technique.

Gli stili APA, Harvard, Vancouver, ISO e altri

29

Li, Xuning, Linghui Liu, Xinyi Ren, Jiajian Gao, Yanqiang Huang e Bin Liu. "Microenvironment modulation of single-atom catalysts and their roles in electrochemical energy conversion". Science Advances 6, n. 39 (settembre 2020): eabb6833. http://dx.doi.org/10.1126/sciadv.abb6833.

Testo completo

Abstract (sommario):

Single-atom catalysts (SACs) have become the most attractive frontier research field in heterogeneous catalysis. Since the atomically dispersed metal atoms are commonly stabilized by ionic/covalent interactions with neighboring atoms, the geometric and electronic structures of SACs depend greatly on their microenvironment, which, in turn, determine the performances in catalytic processes. In this review, we will focus on the recently developed strategies of SAC synthesis, with attention on the microenvironment modulation of single-atom active sites of SACs. Furthermore, experimental and computational advances in understanding such microenvironment in association to the catalytic activity and mechanisms are summarized and exemplified in the electrochemical applications, including the water electrolysis and O2/CO2/N2 reduction reactions. Last, by highlighting the prospects and challenges for microenvironment engineering of SACs, we wish to shed some light on the further development of SACs for electrochemical energy conversion.

Gli stili APA, Harvard, Vancouver, ISO e altri

30

Xu, Kangli, Maogen Zhu, Linqin Zhu, Danying Li, Wanqun Zhang, Tao Huang, Yongchun Zhu e Yitai Qian. "Promoting spherical epitaxial deposition of solid sulfides for high-capacity Li–S batteries". Journal of Materials Chemistry A 8, n. 15 (2020): 7100–7108. http://dx.doi.org/10.1039/c9ta13893e.

Testo completo

Abstract (sommario):

Single-atom Co reconstructs the electronic structure of the solid intermediates, benefits the non-locality of electrons and octahedron–tetrahedron fields of solid intermediates, promotes the electron transfer and Li transport of longitudinal deposition.

Gli stili APA, Harvard, Vancouver, ISO e altri

31

Zorin, Alexander V. "Kuryshkin-Wodkiewicz quantum measurement model for alkaline metal atoms". Discrete and Continuous Models and Applied Computational Science 28, n. 3 (15 dicembre 2020): 274–88. http://dx.doi.org/10.22363/2658-4670-2020-28-3-274-288.

Testo completo

Abstract (sommario):

The constructive form of the Kuryshkin-Wodkiewicz model of quantum measurements was earlier developed in detail for the quantum Kepler problem. For more complex quantum objects, such a construction is unknown. At the same time, the standard (non-constructive) model of Holevo-Helstrom quantum measurements is suitable for any quantum object. In this work, the constructive model of quantum measurements is generalized to a wider class of quantum objects, i.e., the optical spectrum of atoms and ions with one valence electron. The analysis is based on experimental data on the energy ordering of electrons in an atom according to the Klechkovsky-Madelung rule and on the substantiation of a single-particle potential model for describing the energy spectrum of optical electrons in alkali metal atoms. A representation of the perturbation of a single-particle potential in the form of a convolution of the potential of an electron in a hydrogen atom with the Wigner function of a certain effective state of the core in an alkali metal atom representation allows reducing all calculation algorithms for alkali metals to the corresponding algorithms for the hydrogen atom.

Gli stili APA, Harvard, Vancouver, ISO e altri

32

Desfrancois, C., J. P. Astruc, R. Barbe, A. Lagreze e J. P. Schermann. "Electron Transfer Collisions of Excited Sodium Atoms and Oxygen Molecules". Laser Chemistry 6, n. 1 (1 gennaio 1986): 1–14. http://dx.doi.org/10.1155/lc.6.1.

Testo completo

Abstract (sommario):

The vibronic network model is here considered for excited sodium atoms and oxygen molecules collisions. Electronic to vibration transfer and reaction cross sections are computed with a single adjustable parameter : the ionic covalent matrix element. The comparison between the atom-molecule and the quasi-free electron models is presented.

Gli stili APA, Harvard, Vancouver, ISO e altri

33

Mahmoodinia, Mehdi, Mahsa Ebadi, Per-Olof Åstrand, De Chen, Hong-Ye Cheng e Yi-An Zhu. "Structural and electronic properties of the Ptn–PAH complex (n = 1, 2) from density functional calculations". Phys. Chem. Chem. Phys. 16, n. 34 (2014): 18586–95. http://dx.doi.org/10.1039/c4cp02488e.

Testo completo

Abstract (sommario):

The catalytic activity of the Pt atom and dimer can be changed by modifying its chemical surroundings and single layers of Pt atoms have a different catalytic activity as compared to Pt clusters on a carbon surface.

Gli stili APA, Harvard, Vancouver, ISO e altri

34

Stilp, Fabian, Andreas Bereczuk, Julian Berwanger, Nadine Mundigl, Klaus Richter e Franz J. Giessibl. "Very weak bonds to artificial atoms formed by quantum corrals". Science 372, n. 6547 (13 maggio 2021): 1196–200. http://dx.doi.org/10.1126/science.abe2600.

Testo completo

Abstract (sommario):

We explored the bonding properties of the quantum corral (a circle of 48 iron atoms placed on a copper surface) reported by Crommie et al. in 1993, along with variants, as an artificial atom using an atomic force microscope (AFM). The original corral geometry confines 102 electrons to 28 discrete energy states, and we found that these states can form a bond to the front atom of the AFM with an energy of about 5 millielectron volts. The measured forces are about 1/1000 of typical forces in atomically resolved AFM. The confined electrons showed covalent attraction to metal tips and Pauli repulsion to CO-terminated tips. The repulsion at close distance was evident from the response of corral states created by deliberately placing single iron atoms inside the corral. The forces scaled appropriately with a 24-atom corral.

Gli stili APA, Harvard, Vancouver, ISO e altri

35

Vrábel, Viktor, Július Sivý, Peter Šafař e Jozefína Žúžiová. "Crystal, molecular and electronic structure of (5S,8aS)-5-methyl-4,6,7,8,8a,9-hexahydrothieno-[ 3,2-f] indolizinium iodide". Acta Chimica Slovaca 7, n. 2 (1 ottobre 2014): 73–76. http://dx.doi.org/10.2478/acs-2014-0013.

Testo completo

Abstract (sommario):

Abstract The molecules of the title compound, C11H16NS·I, crystallize as single enantiomer with two stereogenic centre, their absolute configuration were confirmed by anomalous dispersion effects in diffraction measurements on the crystals. The conformation of the pyrrolidine ring is close to that of an envelope, with the flap atom N1 displaced by 0.661 (2) A from the plane of the oder remaining four atoms. The central six-membered ring of the indolizine moiety adopt a half-chair conformation with atom C5 displaced by -0.686 (2) Å from the plane of the oder remaining five atoms. The crystal structure of the title compound is stabilized by C-H···I···H-C hydrogen interactions.

Gli stili APA, Harvard, Vancouver, ISO e altri

36

Bae, Y., K. Yang, P. Willke, T. Choi, A. J. Heinrich e C. P. Lutz. "Enhanced quantum coherence in exchange coupled spins via singlet-triplet transitions". Science Advances 4, n. 11 (novembre 2018): eaau4159. http://dx.doi.org/10.1126/sciadv.aau4159.

Testo completo

Abstract (sommario):

Manipulation of spin states at the single-atom scale underlies spin-based quantum information processing and spintronic devices. These applications require protection of the spin states against quantum decoherence due to interactions with the environment. While a single spin is easily disrupted, a coupled-spin system can resist decoherence by using a subspace of states that is immune to magnetic field fluctuations. Here, we engineered the magnetic interactions between the electron spins of two spin-1/2 atoms to create a “clock transition” and thus enhance their spin coherence. To construct and electrically access the desired spin structures, we use atom manipulation combined with electron spin resonance (ESR) in a scanning tunneling microscope. We show that a two-level system composed of a singlet state and a triplet state is insensitive to local and global magnetic field noise, resulting in much longer spin coherence times compared with individual atoms. Moreover, the spin decoherence resulting from the interaction with tunneling electrons is markedly reduced by a homodyne readout of ESR. These results demonstrate that atomically precise spin structures can be designed and assembled to yield enhanced quantum coherence.

Gli stili APA, Harvard, Vancouver, ISO e altri

37

Urch, David S. "BBonding in minerals: the application of PAX (photoelectron and X-ray) spectroscopy to the direct determination of electronic structure". Mineralogical Magazine 53, n. 370 (aprile 1989): 153–64. http://dx.doi.org/10.1180/minmag.1989.053.370.03.

Testo completo

Abstract (sommario):

AbstractX-ray photoelectron spectroscopy can be used to measure the ionization energies of electrons in both valence band and core orbitals. As core vacancies are the initial states for X-ray emission, a knowledge of their energies for all atoms in a mineral enables all the X-ray spectra to be placed on a common energy scale. X-ray spectra are atom specific and are governed by the dipole selection rule. Thus the individual bonding roles of the different atoms are revealed by the fine structure of valence X-ray peaks (i.e. peaks which result from electron transitions between valence band orbitals and core vacancies). The juxtaposition of such spectra enables the composition of the molecular orbitals that make up the chemical bonds of a mineral to be determined.Examples of this approach to the direct determination of electronic structure are given for silica, forsterite, brucite, and pyrite. Multi-electron effects and developments involving anisotropic X-ray emission from single crystals are also discussed.

Gli stili APA, Harvard, Vancouver, ISO e altri

38

MANOHARAN, H. "MAGNETISM AT THE SPATIAL LIMIT". International Journal of Modern Physics B 16, n. 20n22 (30 agosto 2002): 3272. http://dx.doi.org/10.1142/s0217979202014140.

Testo completo

Abstract (sommario):

In this talk I will survey our recent experimental results in the detection and manipulation of magnetism at the spatial limit. Our experiments rely on atom manipulation techniques and scanning tunneling microscopy at low temperatures to enable atomic-scale imaging and control. We have observed "quantum mirages" in focusing devices of order 10 nanometers in size, built by assembling structures out of individual atoms. We have directly imaged the spin perturbations due to isolated magnetic moments on a metal surface. The detection of this localized magnetism can then be utilized in a type of teleportation experiment, in which the spectroscopic signature of an atom is sampled and projected to a remote location by means of a surrounding sea of electrons confined in an engineered nanostructure. The quantum mirage thus cast by a single magnetic atom can be coherently refocused at a distinct point where it is detected as a phantom atom around which the electronic structure mimics that at the real atom. Once materialized, this phantom can interact with real matter in intriguing ways. We have constructed other nanoscale magnetic structures which either elucidate the coupling between isolated moments or provide a mechanism for controlling and exploiting spin coupling over long distances. We have also been developing novel communication methods based on the fundamental effects we have discovered.

Gli stili APA, Harvard, Vancouver, ISO e altri

39

SIDDIQUI, SHAMOON AHMAD. "DFT STUDY OF COFn(n = 1-6) NANO CLUSTERS: AN INVESTIGATION OF SUPERHALOGEN PROPERTIES". Journal of Theoretical and Computational Chemistry 11, n. 04 (16 luglio 2012): 723–34. http://dx.doi.org/10.1142/s0219633612500484.

Testo completo

Abstract (sommario):

Superhalogen properties of CoFn (n = 1 - 6) clusters have been investigated using density functional theory. These calculations reveal the unusual properties of a Cobalt (Co) atom interacting with fluorine (F) atoms. Up to six F atoms are bound to a single Co atom, which results in increase of electron affinities as successive fluorine atoms are attached, reaching a peak value of 7.43 eV for CoF5 . The large HOMO–LUMO energy gap, both in neutral and anionic form, further provide evidence of their stability. These unusual properties brought about by involvement of inner shell 3d-electrons, which not only allow CoFn (n = 1 - 6) clusters to belong to the class of superhalogens but also show that its valence can exceed the nominal value of 2 or 3.

Gli stili APA, Harvard, Vancouver, ISO e altri

40

An, Zhiwei, e Jiang Shen. "Adsorption of rare-earth atoms onl silicon carbide nanotube: a density-functional study". Modern Physics Letters B 28, n. 19 (25 luglio 2014): 1450154. http://dx.doi.org/10.1142/s0217984914501541.

Testo completo

Abstract (sommario):

In this paper, we investigate the adsorption of a series of rare-earth (RE) metal atoms ( La , Pr , Nd , Sm and Eu ) on the pristine zigzag (8, 0) silicon carbide nanotube ( SiCNT ) using density functional theory (DFT). Main focuses are placed on the stable adsorption sites, the corresponding binding energies, and the modified electronic properties of the SiC nanotubes due to the adsorbates. A single RE atom prefers to adsorb strongly at the hollow site with relatively high binding energy (larger than 1.0 eV). Due to the rolling effect of single-walled SiCNTs , the inside configurations are more stable than the outside ones. For RE-adsorbed systems, the adsorption of metal atoms induces certain impurity states within the band gap of the pristine SiCNT . Furthermore, we analyze there exists hybridizations between RE-5d, 6s, C -2p and Si -3p orbitals for the RE atom adsorption on the SiCNTs .

Gli stili APA, Harvard, Vancouver, ISO e altri

41

Zou, Dong-Hui, Min Liang e Wei Chen. "Synthesis, X-Ray Crystal Structures and Catalytic Epoxidation of Oxidovanadium(V) Complexes with Aroylhydrazone and Ethyl Maltolate Ligands". Acta Chimica Slovenica 68, n. 2 (15 giugno 2021): 441–46. http://dx.doi.org/10.17344/acsi.2020.6553.

Testo completo

Abstract (sommario):

Two oxidovanadium(V) complexes, [VOL1L] (1) and [VOL2L] (2) (L = ethyl maltolate), derived from the aroylhydrazones 4-bromo-N’-(2-hydroxy-5-methylbenzylidene)benzohydrazide (H2L1) and N’-(3,5-dibromo-2-hydroxybenzylidene)- 4-methoxybenzohydrazide (H2L2), respectively, have been synthesized and characterized by elemental analysis, infrared and electronic spectroscopy. Structures of the complexes were further confirmed by single crystal X-ray determination. The V atoms in the complexes are coordinated by the ONO donor atoms of the aroylhydrazone ligand, OO donor atoms of the ethyl maltolate ligand, and one oxido O atom, forming octahedral coordination. The complexes function as effective olefin

Gli stili APA, Harvard, Vancouver, ISO e altri

42

Bundhun, Ashwini, Mohammad R. Momeni, Farnaz A. Shakib, Ponnadurai Ramasami, Peter P. Gaspar e Henry F. Schaefer III. "Toward unsaturated stannylenes Y2ZSn: and related compounds with triplet electronic ground states". RSC Advances 6, n. 59 (2016): 53749–59. http://dx.doi.org/10.1039/c6ra00492j.

Testo completo

Abstract (sommario):

Distribution of electrons between the Y₂Z: moiety and the triplet Sn atom in Y₂ZSn: and representations of singlet and triplet Y₂ZSn: and Y₂Z: electronic configurations.

Gli stili APA, Harvard, Vancouver, ISO e altri

43

Ding, Jian Ning, Xiu Qin Wang e Ning Yi Yuan. "DFT Study of Structure, Electronic, Optical and Magnetic Properties of ZnO and Cu-Doped ZnO Clusters". Key Engineering Materials 483 (giugno 2011): 569–73. http://dx.doi.org/10.4028/www.scientific.net/kem.483.569.

Testo completo

Abstract (sommario):

The structure, polarizability and magnetic properties of ZnnOn and Cu-doped Znn-1On (n=2-12, 16) clusters are theoretically investigated using density-functional theory (DFT) at B3LYP/LanL2DZ level. For pure ZnnOn clusters, Zn3O3, Zn8O8 and Zn12O12 are relatively more stable unit, and the ZnnOn clusters with bigger HOMO-LUMO gap tends to have larger <α>/2n. For Cu-doped Znn-1On clusters, the substitution of Zn by Cu atom narrows the HOMO-LUMO gaps and enhances polarizability. In single-doped CuZnn-1On clusters, the magnetic moments of O atoms bonded with Cu atoms are ferromagnetically coupled to the moments of the Cu atoms.

Gli stili APA, Harvard, Vancouver, ISO e altri

44

Li, Dong Mei, Zhi Hua Xiong e Qi Xin Wan. "Density Functional Theory Study of Ti_nO_2n-mClusters (n=1-4, m=0,1)". Advanced Materials Research 507 (aprile 2012): 79–82. http://dx.doi.org/10.4028/www.scientific.net/amr.507.79.

Testo completo

Abstract (sommario):

Using density functional theory, the equilibrium geometries of TinO2n and TinO2n-1 clusters (n=1-4) have been obtained. It suggests that the structures of these two corresponding clusters are changed slightly, except for the number of terminal oxygen atoms. The electronic properties have also been investigated. The bond between Ti and terminal oxygen atom is found to be more covalent than other Ti-O bonds. It also indicates that by deleting one terminal oxygen atom, HOMO is mainly derived from titanium atoms with least coordination, but not from singly-coordination oxygen atoms as that in the stoichiometric clusters. Highest energy levels of least-coordination Ti atoms shift highly and they become more reactive. In addition, HOMO-LUMO energy gaps and binding energies were observed. The calculated results show that the energy gaps decrease quickly, except for Ti4O7 clusters and all the binding energies are relatively large.

Gli stili APA, Harvard, Vancouver, ISO e altri

45

Zongbao, Li, Li Yong, Wang Ying e Wang xia. "Synergistic effect in B and N co-doped Ib-type diamond single crystal: A density function theory calculation". Canadian Journal of Physics 94, n. 9 (settembre 2016): 929–32. http://dx.doi.org/10.1139/cjp-2016-0073.

Testo completo

Abstract (sommario):

Using the first principles density functional theory, diamond crystal doping with B or N atoms, and B/N with different ratios were investigated, based on previous experimental structure results. The formation energies were calculated while the most stable doped structures were obtained for the lowest energy. For comparison, the electronic structures and the micro-mechanism of the doping crystals were discussed. The electronic results show that the doping of N atom is prior to B while the symmetry B–N–B stable structure appears with the N:B = 1:2 doping ratio. And also, the absorption spectrum gives the same results with the experiment for the distinct redshift.

Gli stili APA, Harvard, Vancouver, ISO e altri

46

Alshehri, Mansoor H. "Modeling Interactions of Iron Atoms Encapsulated in Nanotubes". Crystals 11, n. 8 (22 luglio 2021): 845. http://dx.doi.org/10.3390/cryst11080845.

Testo completo

Abstract (sommario):

The behavior and electronic structure of the carbon and boron nitride nanotubes that interact with the iron atom were studied using the Lennard–Jones potential and hybrid discrete-continuum approach. The iron-filled nanotubes were explored by means of classical applied mathematics in order to develop an understanding of the underlying mechanisms of the encapsulation of metal atoms inside nanotubes. Herein, we examined the suction energy and then the equilibrium offset positions of the iron atoms inside zigzag and armchair single-walled nanotubes, to obtain the optimal radii of the tubes and encapsulate the iron atom by determining the radii that provide the minimum interaction energies. Our observations indicate that the encapsulation behaviour depends on the radii of the nanotubes, and we predict that it is less likely for an iron atom to be enclosed inside the nanotubes when the value of the tube radius is less than ≈2.5 Å. The optimal nanotube necessary to fully enclose the iron atom has a radius of ≈4.2 for both carbon and boron nitride nanotubes, which approximately corresponds to the interaction energies of −1.8 kcal/mol. In its entirety, this work presents an approach that might further the understanding of the encapsulation of metal atoms inside nanotubes.

Gli stili APA, Harvard, Vancouver, ISO e altri

47

Aiba, Akira, Madoka Iwane, Shintaro Fujii e Manabu Kiguchi. "Electronic Properties of Single Atom and Molecule Junctions". ChemElectroChem 5, n. 18 (12 settembre 2018): 2508–17. http://dx.doi.org/10.1002/celc.201800787.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

48

Aiba, Akira, Madoka Iwane, Shintaro Fujii e Manabu Kiguchi. "Electronic Properties of Single‐Atom and ‐Molecule Junctions". ChemElectroChem 5, n. 18 (12 settembre 2018): 2507. http://dx.doi.org/10.1002/celc.201801039.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

49

Hu, Pingping, Zhiwei Huang, Zakariae Amghouz, Michiel Makkee, Fei Xu, Freek Kapteijn, Alla Dikhtiarenko, Yaxin Chen, Xiao Gu e Xingfu Tang. "Electronic Metal-Support Interactions in Single-Atom Catalysts". Angewandte Chemie International Edition 53, n. 13 (5 marzo 2014): 3418–21. http://dx.doi.org/10.1002/anie.201309248.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

50

Hu, Pingping, Zhiwei Huang, Zakariae Amghouz, Michiel Makkee, Fei Xu, Freek Kapteijn, Alla Dikhtiarenko, Yaxin Chen, Xiao Gu e Xingfu Tang. "Electronic Metal-Support Interactions in Single-Atom Catalysts". Angewandte Chemie 126, n. 13 (5 marzo 2014): 3486–89. http://dx.doi.org/10.1002/ange.201309248.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Articoli di riviste sul tema "Single atom electronics"

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili