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Journal of Theoretical and Applied Physics (JTAP)

Editor-in-Chief: Davoud Dorranian

Online ISSN: 2251-7235

Print ISSN: 2251-7227

Publishes Bimonthly

Volume 13 (2019)

Issue 4, September 2019

The experimental approach into the influence of external inductance on the discharge characteristic of HiPIMS

AbstractThe main objective of the current paper is to describe the effect of external inductance (EI) on the current discharge waveforms of HiPIMS at different pulse-on time (Pon) and its relation with static deposition rate and topographical properties of deposited titanium thin films, which is investigated by scanning electron microscope and atomic force microscope. It […]

Memory effect in silicon nitride deposition using ICPCVD technique

AbstractIn this study, a plasma-based low-temperature, low-pressure SiN film deposition is investigated for device applications. Ammonia, nitrogen and silane are being used for optimization of the quality of SiN film for device passivation by ICPCVD. Characterization of SiN film is done using elastic recoil detection analysis, AFM, FTIR and ellipsometry. The effect of previous process […]

Detection of overtone and combined peaks using Mn/Cu helical star-shaped (pine-tree-like) sculptured thin films in surface-enhanced Raman spectroscopy

AbstractMn helical star-shaped (pine-tree-like) nano-sculptured thin films with three-, four-and fivefold symmetry on copper substrates were produced using oblique angle deposition method in conjunction with rotation of sample holder at certain angles. Raman spectroscopy of the samples which were subjected to impregnation by 4,4′-bipyridine (C10H8N2) solution was carried out by 632.8 nm wavelength laser. The analysis […]

Investigation of dopant centres dominating the conduction process in the bulk of un-doped GaSb

AbstractIn this paper, first, the theoretical description of the effects of the dopant densities and the activation energies on the ionization densities, the chemical potentials corresponding to each dopant levels, the majority carrier densities and the Fermi-energy levels in one-acceptor-level system, highly compensated system and two-acceptor-level system are described in detail. Upon fitting the theoretical […]

Effects of different gas flow rates and non-perpendicular incidence angles of argon cold atmospheric-pressure plasma jet on silver thin film treatment

AbstractIn this study, the influences of variations in the gas flow rate and incidence angles of argon cold atmospheric-pressure plasma jet on the morphology and absorption spectra of silver thin films (60 nm, 80 nm, and 100 nm film thickness) are investigated. To evaluate the surface morphology, atomic force microscopy (AFM) was employed on the silver thin film […]

Electrical behavior of graphene under temperature effect and survey of I–T curve

AbstractGraphene flakes were made from electrochemical exfoliation. To study graphene planes, different volumes of graphene solutions (1, 2, 4, and 7 ml) were sprayed on glass lamellae to get different graphene planes. I–V curve of all samples shows ohmic behavior with resistance in the order of kΩ which increases the slope of the I–V curve with […]

Effect of BN nanodots on the electronic properties of α- and β-graphyne sheets: a density functional theory study

AbstractThe effect of BN nanodots with hexagonal shape on the electronic properties of α- and β-graphyne sheets is investigated. The structural and electronic properties of α- and β-graphyne sheets doped with BN nanodots are studied by using density functional theory. The cohesive energies of the systems indicate all considered structures are thermally stable. It is […]

Effect of plasma oxidation parameters on physical properties of nanocrystalline nickel oxide thin films grown by two-step method: DC sputtering and plasma oxidation

AbstractNanocrystalline nickel oxide (NiO) thin films were successfully grown on quartz substrates by two-step method. In the first step, nickel films were deposited on quartz substrates by DC magnetron sputtering technique. Then, the plasma oxidation of nickel films was used for preparation of nickel oxide. The effect of DC plasma power and treatment time on […]

Density functional theory study on the effect of Cu- and Na-substituted layers on spin-dependent transport and TMR in the Fe/ZnO/Fe MTJ

AbstractUsing density functional theory, effects of Na- and Cu-substituted layers on the spin-dependent electronic transport properties of Fe/ZnO/Fe magnetic tunnel junction based on zinc oxide barrier tunnel, with rock-salt crystalline structure, have been studied. In zero-bias voltage, conductance and tunneling magneto-resistance (TMR) ratio of structures are calculated. It is showed that substituted layers in the […]

Photon decaying in de Sitter universe

AbstractThe interaction between three photons is studied in de Sitter ambient space formalism. As a special case, the half harmonic generator is considered, i.e., one photon decays to two same-energy photons. The scattering matrix elements are presented which define the indirect gravitational effect on quantum field theory. The null curvature limit of scattering matrix is […]