Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 15

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

Search:
in the keywords:  79.20.Rf
help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

The Trajectory Dependent Scattering οf Li Ions by Al Substrate

100%
Král V.
Acta Physica Polonica A
|
2009
|
vol. 116
|
issue 2
238-239
EN
The trajectory dependent scattering of Li ions by Al substrate is studied. It is shown that besides primary elastic peak there exists a subsidiary peak about one-third energy of incident ions. The dependence of trajectory is achieved by shifting of the incident beam along x axis. The results have been compared with the results of Na scattering that have been published recently.
2
Content available remote

Comprehensive Analysis of Ion Beam Induced Stainless Steel Surface Morphology

100%
Kowalski Z.
Acta Physica Polonica A
|
2011
|
vol. 120
|
issue 1
70-74
EN
Surface morphology, one of the various physical properties modified by ion beam irradiation, is usually characterized by well known and very often investigated surface topography and surface roughness. The paper presents two additional aspects of surface morphology modification (called by the author: profile variability and surface morphology arrangement) that seem to be good complementary indicators of morphology changes. Surface micro- and nanotopographies were observed by means of scanning electron and near-field microscopes. High quality profilograph and atomic force microscope were utilised to measure main selected roughness parameters (based on the well known surface profiles). To detect any profile shape alteration during ion beam bombardment fractal analysis was used, and especially fractal dimension D that can give information about a rate p_{v} of profile shape variability. Surface morphology arrangement, i.e. a question whether it is random or determined, was studied with the use of frequency plots resulting from harmonic analysis of profiles. Surface topographies, selected roughness parameters, fractal dimensions and frequency plots relating to stainless steel of 1H18N9T (made in Poland) bombarded with perpendicular (Θp = 0°) as well as very inclined (Θp = 85-87°) beam were examined. Low energy (0.8 keV) broad argon ion beam and neutralized narrow argon or krypton ion beams (up to 6 keV) were used in the experiments.
3
Content available remote

Ion Beam Sputtering Monitored by Optical Spectroscopy

63%
El Fqih M., Fournier P.
Acta Physica Polonica A
|
2009
|
vol. 115
|
issue 5
901-904
EN
Optical spectroscopy gives a simple means to follow the evolution of the surface composition during ion beam sputtering. This is illustrated by three examples: air oxidised metals (Al and Cu), various CuAl alloys and the Cu_{98}Be_2 alloy. Several time scales are distinguished, corresponding to different processes: the elimination of surface contaminants, the removal of the corroded layer. The implications for the use of ion beam optical spectroscopy in surface analysis are discussed.
4
Content available remote

Molecular Dynamics Simulations of Energetic Ar Cluster Bombardment of Ag(111)

51%
Palka G., Rzeznik L., Paruch R., Postawa Z.
Acta Physica Polonica A
|
2013
|
vol. 123
|
issue 5
831-833
EN
Large-scale molecular dynamics computer simulations are used to investigate the dynamics of material ejection during high-energy Ar_n cluster bombardment of Ag(111) at normal incidence. The silver sample containing 7 million atoms is bombarded with Ar_n projectiles (n=45-30000) with kinetic energy spanning from a few keV up to 1 MeV. Such a wide range of projectile parameters allows probing processes taking place during low-density collision cascade as well as during high-density events characteristic of micrometeorite bombardment in space. The material modifications and total sputtering yield of ejected particles are investigated. While at low-energy impacts, ejection of individual silver atoms is the main emission channel, the ejection of large clusters from the corona of the created crater dominates for the high-energy impacts.
5
Content available remote

Charge Transfer Dynamics in Atom-Metal Surface Collisions

51%
Wiertel M., Taranko R., Taranko E.
|
|
vol. 96
|
issue 6
769-783
EN
We study the charge exchange in atom-metal collisions in the framework of the generalized time-dependent Anderson-Newns model. The electron correlations and correlated hopping are treated within the mean-field approximation. The resulting one-particle model with an effective spin-dependent atom-surface coupling is used to study the charge transfer in scattering of Na and Li atoms on metal surfaces. It is shown that the effective occupation dependent atom-surface coupling influences mainly the expectation values for producing positive, neutral, and negative particles for small work functions and high atom velocities. It is also shown that the temperature dependence of these expectation values is more visible, especially for magnetic solutions.
6
Content available remote

Presence of Inductivity in (CoFeZr)_x(PZT)_{1-x} Nanocomposite Produced by Ion Beam Sputtering

51%
Kołtunowicz T., Żukowski P., Boiko O., Fedotov A., Larkin A.
Acta Physica Polonica A
|
2015
|
vol. 128
|
issue 5
853-856
EN
This paper presents the investigations of the electrical properties of the (CoFeZr)_{x}(PZT)_{1-x} nanocomposite with the metallic phase content x=43.8 at.%, which was produced by ion beam sputtering. Such preparation took place under an argon atmosphere with low oxygen content with its partial pressure P_{O₂} = 2×10¯³ Pa. The measurements were performed using alternating current within the frequency range of 50 Hz-10⁵ Hz for measuring temperatures ranging from 238 K to 328 K. The (CoFeZr)_{43.8}(PZT)_{56.2} nanocomposite sample subjected to a 15 min annealing process in air at the temperature Tₐ=423 K demonstrates a phase angle of -90° ≤ θ ≤ 0° in the frequency range 50 Hz-10⁵ Hz. It corresponds to the capacitive type of conduction. In the frequency range 10⁴-10⁵ Hz sharp minima in selected conductivity vs. frequency characteristics occur, which corresponds to a current resonance phenomenon in RLC circuits. In case of a sample annealed at Tₐ=498 K the inductive type of conduction with 0° ≤ θ ≤ +90° occurs in a high frequency area. At the frequency f_{r} characterized by the phase angle θ = 0°, the capacity value reaches its local minimum. It indicates a voltage resonance phenomenon in conventional RLC circuits. The θ = +90° crossing in the frequency dependence of phase angle corresponds to the current resonance phenomenon, which is represented by a strong local minimum in the conductivity vs. frequency characteristics.
7
Content available remote

Annealing of (CoFeZr)_{x}(CaF_2)_{100-x} Nanocomposites Produced by the Ion-Beam Sputtering in the Ar and O_2 Ambient

51%
Kołtunowicz T., Zhukowski P., Bondariev V., Fedotova J., Fedotov A.
Acta Physica Polonica A
|
2013
|
vol. 123
|
issue 5
932-934
EN
This paper presents the investigations of electrical properties and effect of annealing on conductivity of (CoFeZr)_{x}(CaF_2)_{100-x} nanocomposites produced by ion-beam sputtering in the Ar and O_2 ambient. Investigations into conductivity of (CoFeZr)_{x}(CaF_2)_{100-x} nanocomposites depending on the measuring temperature and the annealing temperature have been performed. The application of a combined argon-oxygen beam brings about lowering of the potential barrier on the surface of nanoparticles. In the course of annealing the additional oxidation occurs. First it proceeds on the surface and then all through the metallic-phase particles.
8
Content available remote

Effect of N₂⁺ Ion Implantation and Thermal Annealing on Near-Surface Layers of Implanted GaAs

51%
Kulik M., Surowiec Z., Rzodkiewicz W., Filiks J., Drozdziel A.
Acta Physica Polonica A
|
2015
|
vol. 128
|
issue 5
918-922
EN
The surface of semi-isolating GaAs (100) was irradiated with a fluence of 6×10¹⁷ cm¯² of the N₂⁺ ion beam; then, the samples were thermally annealed at temperatures of 500, 700, and 900°C for 2 h in an argon gas flow. The surface roughness of implanted samples was investigated with the help of atomic force microscopy. Numerous hillocks, which caused a significant increase in surface roughness, were observed. The spectroscopic ellipsometry method was used for determination of pseudo-dielectric functions of the near-surface layers in the investigated samples and the thickness of native oxides covering the irradiated surface. It was observed that the shapes of disorder spectra of the dielectric functions of near-surface layers of implanted GaAs partly returned to their original state after the thermal annealing.
9
Content available remote

The Features of Real Part of Admittance in the Nanocomposites (Fe_{45}Co_{45}Zr_{10})_{x}(Al_2O_3)_{100 - x} Manufactured by the Ion-Beam Sputtering Technique with Ar Ions

51%
Kołtunowicz T., Zhukowski P., Fedotova V., Saad A., Larkin A., Fedotov A.
Acta Physica Polonica A
|
2011
|
vol. 120
|
issue 1
35-38
EN
The temperature and frequency dependences of the admittance real part σ (T, f) in granular (Fe_{45}Co_{45}Zr_{10})_{x}(Al_2O_3)_{100 - x} nanocomposite films around the percolation threshold x_{C} were investigated. The behaviour of σ (T, f) vs. the temperature and frequency over the ranges 77-300 K and 50 Hz-1 MHz, respectively, displays the predominance of an activation (hopping) conductance mechanism for the samples below the percolation threshold x_{C} and of a metallic one beyond the x_{C} determined as 54 ± 2 at.%. The mean hopping range d for the nanoparticles diameter D was estimated at different metallic phase content x.
10
Content available remote

Hopping Conductance in Nanocomposites (Fe_{0.45}Co_{0.45}Zr_{0.10})_{x}(Al_2O_3)_{1 - x} Manufactured by Ion-Beam Sputtering of Complex Target in Ar+O_2 Ambient Gas

51%
Kołtunowicz T., Zhukowski P., Fedotova V., Saad A., Fedotov A.
Acta Physica Polonica A
|
2011
|
vol. 120
|
issue 1
39-42
EN
We report the investigation of a real part of the admittance σ of granular nanocomposites (Fe_{0.45}Co_{0.45}Zr_{0.10})_{x}(Al_2O_3)_{1 - x} with 0.30 < x < 0.70 in the dielectric (hopping) regime. An analysis of the σ(T, f, x) dependences in the as-deposited and annealed films over the temperature 77 K < T < 300 K and frequency 50 < f < 10^6 Hz ranges displayed the predominance of an activation (hopping) conductance mechanism with dσ/ dT > 0 for the samples below the percolation threshold x_{C} ≈ 0.76 ± 0.05. Based on the earlier models for hopping AC conductance, computer simulation of the frequency coefficient α_{f} of hopping conductance depending on the probability of jump p, frequency f, and also on the shape of σ(f) curve was performed. The experimental and simulation results revealed a good agreement.
11
Content available remote

Voltage and Current Resonance in Nanocomposite (FeCoZr)_x(CaF₂)_{100-x} Produced by Ion-Beam Sputtering in Pure Argon Atmosphere

51%
Koltunowicz T., Zukowski P., Bondariev V., Fedotov A., Svito I., Fedotova J., Saad A.
Acta Physica Polonica A
|
2015
|
vol. 128
|
issue 5
897-900
EN
In this paper the results of investigations of electrical properties of metal-dielectric nanocomposites (FeCoZr)_x(CaF₂)_{100-x} are presented. The samples with the metallic phase content x=45.7 at.% were produced by ion-beam sputtering method in pure argon atmosphere, and subsequently annealed at 398 K for 15 min. The measurements of electrical properties were performed in the frequency range from 50 Hz to 1 MHz. The frequency dependences of phase angle θ, capacity C_{p}, conductivity σ and dielectric loss factor tanδ were measured at seven different temperatures ranging from 148 K to 263 K. It was found that the nanocomposite exhibits the phenomena of voltage resonance and current resonance, characteristic of the conventional RLC circuits with series and parallel connections of elements.
12
Content available remote

Dielectric Properties of (CoFeZr)_x(PZT)_{100-x} Nanocomposites Produced with a Beam of Argon and Oxygen Ions

51%
Koltunowicz T.
|
|
vol. 125
|
issue 6
1412-1415
EN
In this paper it was established that nanocomposite (FeCoZr)_x(PZT)_{100-x}, with x=90.0 at.%, produced by ion sputtering with argon and oxygen beam remains under the percolation threshold. It is related to the compound structure of films and creation of coat consisting of metallic oxides on surface of metallic phase nanogranules, which prevents electric contact between nanoparticles. Verification of the Arrhenius dependences for capacity and conductivity demonstrates that dominant part of metallic phase nanogranules has metal oxide coatings. Only a small number of nanogranules (probably around a few percent) does not have oxide coating.
13
Content available remote

Sputtering of Benzene Sample by Large Ne, Ar and Kr Clusters - Molecular Dynamics Computer Simulations

45%
Rzeznik L., Paruch R., Garrison B., Postawa Z.
Acta Physica Polonica A
|
2013
|
vol. 123
|
issue 5
825-827
EN
Molecular dynamics simulations are employed to probe the role of an impact angle on emission efficiency of organic molecules sputtered from benzene crystal bombarded by 15 keV Ne_{2953}, Ar_{2953}, and Kr_{2953} clusters. It is found that both the cluster type and the angle of incidence have significant effect on the emission efficiency. The shape of the impact angle dependence does not resemble the dependence characteristic for medium size clusters (C_{60}, Ar_{366}), where sputtering yield only moderately increases with the impact angle, has a shallow maximum around 40° and then decreases. On the contrary, for the large projectiles (Ne_{2953}, Ar_{2953}, and Kr_{2953}) the emission efficiency steeply increases with the impact angle, has a pronounced maximum around 55° followed by rapid signal decay. It has been found that the sputtering yield is the most sensitive to the impact angle change for Kr cluster projectiles, while change of the impact angle of Ne projectile has the smallest effect on the efficiency of material ejection.
14
Content available remote

Influence of Hot Implantation on Residual Radiation Damage in Silicon Carbide

38%
Rawski M., Żuk J., Kulik M., Droździel A., Lin L., Prucnal S., Pyszniak K., Turek M.
Acta Physica Polonica A
|
2011
|
vol. 120
|
issue 1
192-195
EN
Remarkable thermomechanical and electrical properties of silicon carbide (SiC) make this material very attractive for high-temperature, high-power, and high-frequency applications. Because of very low values of diffusion coefficient of most impurities in SiC, ion implantation is the best method to selectively introduce dopants over well-defined depths in SiC. Aluminium is commonly used for creating p-type regions in SiC. However, post-implantation radiation damage, which strongly deteriorates required electric properties of the implanted layers, is difficult to anneal even at high temperatures because of remaining residual damage. Therefore implantation at elevated target temperatures (hot implantation) is nowadays an accepted method to decrease the level of the residual radiation damage by avoiding ion beam-induced amorphization. The main objective of this study is to compare the results of the Rutherford backscattering spectroscopy with channeling and micro-Raman spectroscopy investigations of room temperature and 500°C Al^{+} ion implantation-induced damage in 6H-SiC and its removal by high temperature (up to 1600°C) thermal annealing.
15
Content available remote

Ion and Electron Beam Induced Luminescence οf Rare Earth Doped YAG Crystals

23%
Gawlik G., Sarnecki J., Jóźwik I., Jagielski J., Pawłowska M.
Acta Physica Polonica A
|
2011
|
vol. 120
|
issue 1
181-183
EN
The aim of this work was the evaluation of ion-beam induced luminescence for the characterization of luminescent oxide materials containing rare earth elements. The yttrium aluminium garnet epilayers doped with Nd, Pr, Ho, and Tm atoms were used. The ion-beam induced luminescence spectra were excited using 100 keV H_2^{+} ion beam and were recorded in the wavelengths ranging from 300 nm up to 1000 nm. The separate parts of the surface of the same samples were used for ion-beam induced luminescence and cathodoluminescence experiments. Cathodoluminescence spectra have been recorded in the range from 370 nm up to 850 nm at 20 keV e-beam in scanning electron microscope equipped with a grating spectrometer coupled with a photomultiplier. The observed narrow ion-beam induced luminescence lines can be ascribed to the well known radiative transitions in the rare-earth ions in the YAG crystals. The cathodoluminescence spectra reveal essentially the same emission lines as ion-beam induced luminescence. The decrease of the ion-beam induced luminescence lines intensity has been observed under the increasing ion fluences. The ion-beam induced luminescence may be used for characterization of transparent luminescent materials as an alternative method for cathodoluminescence and can be especially useful for observation of ion-beam damage formation in crystals.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.