scholarly journals Modification of Pyrolyzed Polyacrylonitrile with Silver Atoms

2020 ◽  
pp. 32-41
Author(s):  
Irina Zaporotskova ◽  
◽  
Olesia Kakorina ◽  
Igor Kakorin ◽  
◽  
...  
Keyword(s):  
Electron Energy ◽  
Silver Atom ◽  
Theoretical Calculations ◽  
Energy State ◽  
Polymer Surface ◽  
Molecular Cluster ◽  
Metal Composite ◽  
New Materials ◽  
Metal Atoms ◽  
Silver Atoms

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.

scholarly journals Chemical identification through two-dimensional electron energy-loss spectroscopy

2020 ◽  
Vol 6 (28) ◽  
pp. eabb4713
Author(s):  
Renwen Yu ◽  
F. Javier García de Abajo
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Electronic Device ◽  
Theoretical Calculations ◽  
Chemical Species ◽  
High Sensitivity ◽  
Two Dimensional ◽  
Excitation Spectra ◽  
Electron Energy Loss

We explore a disruptive approach to nanoscale sensing by performing electron energy loss spectroscopy through the use of low-energy ballistic electrons that propagate on a two-dimensional semiconductor. In analogy to free-space electron microscopy, we show that the presence of analyte molecules in the vicinity of the semiconductor produces substantial energy losses in the electrons, which can be resolved by energy-selective electron injection and detection through actively controlled potential gates. The infrared excitation spectra of the molecules are thereby gathered in this electronic device, enabling the identification of chemical species with high sensitivity. Our realistic theoretical calculations demonstrate the superiority of this technique for molecular sensing, capable of performing spectral identification at the zeptomol level within a microscopic all-electrical device.

scholarly journals Plasmonic Metalattices: A Correlated Monochromated Electron Energy Loss Study and Theoretical Calculations

2019 ◽  
Vol 25 (S2) ◽  
pp. 678-679
Author(s):  
Parivash Moradifar ◽  
Lei Kang ◽  
Pratibha Mahale ◽  
Yunzhi Liu ◽  
Nabila N. Nova ◽  
...  
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Theoretical Calculations ◽  
Electron Energy Loss

scholarly journals Linear and Nonlinear Intersubband Optical Properties of Direct Band Gap GeSn Quantum Dots

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 124 ◽  
Author(s):  
Mourad Baira ◽  
Bassem Salem ◽  
Niyaz Madhar ◽  
Bouraoui Ilahi
Keyword(s):  
Quantum Dots ◽  
Refractive Index ◽  
Absorption Coefficient ◽  
Electron Energy ◽  
Energy State ◽  
Total Absorption ◽  
Absorption Coefficients ◽  
Third Order ◽  
Index Changes ◽  
Total Absorption Coefficient

Intersubband optical transitions, refractive index changes, and absorption coefficients are numerically driven for direct bandgap strained GeSn/Ge quantum dots. The linear, third-order nonlinear and total, absorption coefficients and refractive index changes are evaluated over useful dot sizes’ range ensuring p-like Γ-electron energy state to be lower than s-like L-electron energy state. The results show strong dependence of the total absorption coefficient and refractive index changes on the quantum dot sizes. The third order nonlinear contribution is found to be sensitive to the incident light intensity affecting both total absorption coefficient and refractive index changes, especially for larger dot sizes.

Optical emission and absorption studies of silver atoms in rare gas matrixes at 12 K; silver atom cryophotoaggregation

1980 ◽  
Vol 102 (26) ◽  
pp. 7702-7709 ◽  
Author(s):  
S. A. Mitchell ◽  
J. Farrell ◽  
G. A. Kenney-Wallace ◽  
G. A. Ozin
Keyword(s):  
Silver Atom ◽  
Optical Emission ◽  
Rare Gas ◽  
Absorption Studies ◽  
Silver Atoms

Synthesis and characterization of new materials with pyrrole units and their semiconductor behavior

2016 ◽  
Vol 1819 ◽  
Author(s):  
Olivia Monroy ◽  
Lioudmila Fomina ◽  
Roberto Salcedo
Keyword(s):  
Aromatic Ring ◽  
Aromatic Amines ◽  
Organic Materials ◽  
Theoretical Calculations ◽  
Synthesis And Characterization ◽  
New Materials ◽  
Semiconductor Behavior ◽  
Semiconducting Behavior

ABSTRACTNew organic materials with semiconductor behavior were prepared from diphenyldiacetylene and aromatic amines with withdrawing groups by Reisch-Schulte reaction and characterized by IR, RMN spectroscopy. The obtained materials share the property of having electron withdrawing groups joint to the attached aromatic ring, it seems this feature accounts in large fashion to improve the semiconducting behavior of this kind of substances, this topic was studied by means theoretical calculations and the results are also discussed. The calculations were carried out by means the Gaussian09 software and all the involved species were geometrically optimized.

Diphenyl(1-pyridyl)phosphine Sulfide as a Ligand in Mono-and Binuclear Coinage Metal Complexes

1997 ◽  
Vol 52 (3) ◽  
pp. 385-390 ◽  
Author(s):  
M. Elena Olmos ◽  
Annette Schier ◽  
Hubert Schmidbaur
Keyword(s):  
Metal Complexes ◽  
Silver Atom ◽  
Gold Atom ◽  
X Ray Diffraction ◽  
Coinage Metal ◽  
X Ray ◽  
Metal Atoms ◽  
Tetrahedral Environment ◽  
Mixed Metal Complexes ◽  
Phosphine Sulfide

Abstract Diphenyl(1-pyridyl)phosphine sulfide, Ph2pyPS, 1, gives a 1:1 complex (2) with AuCl upon treatment with (C4H8S)AuCl. According to an X -ray diffraction analysis, this compound is isomorphous with the Ph3PS complex. [Ph3PAu]BF4 and 1 give the cationic complex [Ph3PAuSPpyPh2]BF4 (3 ) . With two equivalents of the same reagent the binuclear complex 4 is generated, in which the metal atoms are S- and N-bonded. The reaction of 2 equivalents of 1 with [(tetrahydrothiophene)2Au]ClO4 affords the 2:1 complex 5 with the gold atom exclusively S-bonded. The analogous reaction with AgBF4 gives the 2:1 complex 6, the structure of which has also been determined by X-ray diffraction. The silver atom is engaged in coordinative bonding with both sulfur and both nitrogen atoms in a quasi-tetrahedral environment. Addition of AgClO4 to com pound 5, and of [(MeCN)4Cu]B F4 to 6, gives mixed-metal complexes (7, 8) with head-to-head structures, the silver atoms being exclusively S-bonded.

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