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Full-Text Articles in Physical Sciences and Mathematics

On Certain Modified Meyer-König And Zeller Operators, Lucyna Rempulska, Karolina Tomczak Jan 2006

On Certain Modified Meyer-König And Zeller Operators, Lucyna Rempulska, Karolina Tomczak

Turkish Journal of Mathematics

We introduce certain modified Meyer-König and Zeller operators and we study their approximation properties. The similar results for modified Bernstein polynomials were given in [6].


Mineral-Chemical Constraints On The Miocene Calc-Alkaline And Shoshonitic Volcanic Rocks Of Western Turkey: Disequilibrium Phenocryst Assemblages As Indicators Of Magma Storage And Mixing Conditions, Ercan Aldanmaz Jan 2006

Mineral-Chemical Constraints On The Miocene Calc-Alkaline And Shoshonitic Volcanic Rocks Of Western Turkey: Disequilibrium Phenocryst Assemblages As Indicators Of Magma Storage And Mixing Conditions, Ercan Aldanmaz

Turkish Journal of Earth Sciences

Early to Middle Miocene (22 to 15 Ma) volcanic activity across western Turkey produced a series of lavas and pyroclastic deposits with calc-alkaline and shoshonitic affinities. The erupted magmas show a broad range of compositions from basaltic to rhyolitic (48-75 SiO2 wt%) and are composed of variable phenocryst assemblages. Petrographic and mineral-chemical characteristics suggest that the magmas underwent hydrous crystallization in deep crustal magma chambers that was dominated by plagioclase + pyroxene + pargasitic amphibole fractionation. Subsequent crystallization in shallower magma chambers followed two different trends: (1) anhydrous (pyroxene + plagioclase-dominated); and (2) hydrous (plagioclase + edenitic amphibole + pyroxene-dominated). …


Petrography And Geochemistry Of Paragneisses In The Çine Submassif Of The Menderes Massif, Western Anatolia, Firat Şengün, Osman Candan, O. Özcan Dora, O. Ersi̇n Koralay Jan 2006

Petrography And Geochemistry Of Paragneisses In The Çine Submassif Of The Menderes Massif, Western Anatolia, Firat Şengün, Osman Candan, O. Özcan Dora, O. Ersi̇n Koralay

Turkish Journal of Earth Sciences

The Menderes Massif, which covers a large area in western Turkey, is made up of Pan-African basement rocks and a Palaeozoic to Early Tertiary cover sequence. The study area is located in the Dalama and Hallaçlar (Aydın) area, in the northern and central parts of the Çine submassif of the Menderes Massif. The oldest units of the Pan-African basement are metaclastics, consisting of paragneisses and mica schists that gradually and conformably overlay paragneisses. Macroscopic appearances and mineralogical and textural data indicate that paragneisses can be subdivided into four subgroups. These are: (1) black spotted, (2) white spotted, (3) massive, grey-coloured …


An Ann Based Approach To Improve The Distance Relaying Algorithm, Hassan Khorashadi Zadeh, Zuyi Li Jan 2006

An Ann Based Approach To Improve The Distance Relaying Algorithm, Hassan Khorashadi Zadeh, Zuyi Li

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an artificial neural network- (ANN) based approach to improve the performance of the distance relaying algorithm. The proposed distance relay uses magnitudes of voltages and currents as input signals to find fault locations. In this approach, an ANN has been included in the protection algorithm as an extension of the existing methods, which improves the reliability of the protection operation. The design procedure of the proposed relay is presented in detail. Simulation studies are performed and the influence of changing system parameters, such as fault resistance and source impedance, is studied. Performance studies show that the proposed …


Surface Modification Of Glass Beads With An Aminosilane Monolayer, Gülşi̇n Arslan, Mustafa Özmen, Beni̇z Gündüz, Xunli Zhang, Mustafa Ersöz Jan 2006

Surface Modification Of Glass Beads With An Aminosilane Monolayer, Gülşi̇n Arslan, Mustafa Özmen, Beni̇z Gündüz, Xunli Zhang, Mustafa Ersöz

Turkish Journal of Chemistry

Surface modification of glass beads with a self-assembled monolayer of (3-Aminopropyl)-triethoxysilane (APTES) was investigated. Characterisation of the self-assembled monolayer was confirmed by a reaction between amine terminal groups and thionylchloride of Rhodamine-B dye using fluorescence microscopy. Quantitative 3-dimensional profiling was obtained for all modification processes by converting microscopic images to numerical values. The reaction steps were also analysed using infrared spectroscopy (FTIR).


Metal Complexes Of Schiff Bases: Preparation, Characterization, And Biological Activity, Gehad Genidy Mohamed, Mohamed Mohamed Omar, Ahmed Mohamed Hindy Jan 2006

Metal Complexes Of Schiff Bases: Preparation, Characterization, And Biological Activity, Gehad Genidy Mohamed, Mohamed Mohamed Omar, Ahmed Mohamed Hindy

Turkish Journal of Chemistry

Metal complexes of Schiff bases derived from 2-furancarboxaldehyde and o-phenylenediamine (L^1), and 2-thiophenecarboxaldehyde and 2-aminothiophenol (HL^2) are reported and characterized based on elemental analyses, IR ^1H NMR, solid reflectance, magnetic moment, molar conductance, and thermal analysis (TGA). The ligand dissociation, as well as the metal-ligand stability constants were calculated, pH-metrically, at 25 °C and ionic strength \mu = 0.1 (1 M NaCl). The complexes are found to have the formulae [M(L^1)(H_2O)_2](Cl)_n \cdot yH_2O (where M = Fe(III), Ni(II), Cu(II); n = 2-3, y = 2-4); [M(L^1)](X)_2 \cdot yH_2O (where M = Co(II), Zn(II), UO_2(II), X = Cl, AcO or NO_3, …


Dwba Of The Reaction ^0be(P, \Alpha )^6li At E_P = 18.6\Sim 50 Mev, S. E. Abdel-Kariem Jan 2006

Dwba Of The Reaction ^0be(P, \Alpha )^6li At E_P = 18.6\Sim 50 Mev, S. E. Abdel-Kariem

Turkish Journal of Physics

The compound nucleus produced in the reaction ^9Be(p, \alpha)^6Li in the incident energy range E_p = 18.6 \sim 50 MeV is mainly occurred when its excitation energy is greater than the \alpha -particle threshold separation energy by about 20 MeV, strongly suggesting the reaction mechanism is a direct one-step process. To understand this phenomenon, we employ semi-microscopic zero-range distorted-wave Born approximation (DWBA) theory to analyse experimental data obtained in this energy range for the lower three ^6Li-states: ground state (1^+; 0); 2.186 MeV (3^+; 0); and 3.563 MeV (0^+; 1). The Kurath-Millener spectroscopic-factor amplitudes for the triton-cluster transfer are used …


Profiling Of Lithium And Potassium Into Silicon, Ali M. Mousa Jan 2006

Profiling Of Lithium And Potassium Into Silicon, Ali M. Mousa

Turkish Journal of Physics

The profiling of Lithium and Potassium into Silicon doped by electro deposition from molten salts (LiBr, KI) has been studied for various time periods and deposition currents. For the samples studied, changes in the deposition time and current have significant effects on the conductivity type and sheet resistance variation. This has been attributed to the high value of solid solubility of Lithium and Potassium in Silicon. Additionally, surface concentration variation with depth is affected significantly by variation in deposition time, particular for samples with a deposition time of 7 minutes. A junction was found 156 microns from the surface. For …


Optical Pulse Distortion In Fibonacci-Class Multilayer Stacks, A Rostami, S. Matloub Jan 2006

Optical Pulse Distortion In Fibonacci-Class Multilayer Stacks, A Rostami, S. Matloub

Turkish Journal of Physics

Optical pulse distortion and propagation through quasi-periodic structures generally and especially for Fibonacci-class, is investigated analytically and simulated numerically. In this analysis, the transfer matrix method (TMM) for distortion evaluation is used. The simulated results for Fibonacci-class quasi-periodic structures and pure periodic multilayer stacks are compared. We show that the Fibonacci-class quasi-periodic structure has a large dispersion coefficient with respect to a similar case in the periodic structure. So, quasi-periodic structures will destroy the incident pulse shape for smaller stack length than a periodic case in a similar situation. Finally, using output power, the distortion limit can be estimated and …


Inexpensive Near-Ir Photodetector, Omar A. Abdulrazaq, Evan T. Saleem Jan 2006

Inexpensive Near-Ir Photodetector, Omar A. Abdulrazaq, Evan T. Saleem

Turkish Journal of Physics

Fabrication and characterization of a CdS/Si heterojunction detector for 1.064 \mu m Nd:YAG laser detection has been carried out by pyrolytic spraying of CdS films onto single crystal n-type Si substrates. Response time has been determined in this study.


Tensor Polarization And Quadrupole Form Factor Of The Deuteron, A. K. A. Azzam, M. A. Fawzy, E. M. Hassan, A. M. Yasser Jan 2006

Tensor Polarization And Quadrupole Form Factor Of The Deuteron, A. K. A. Azzam, M. A. Fawzy, E. M. Hassan, A. M. Yasser

Turkish Journal of Physics

A new experimental value, M = 0.06925 \pm 0.00281, of the peak of the quadrupole form factor F_Q(q) is obtained by fitting the straight line relation found between the peak values of both T_{21}(q) and F_Q(q).


Transient Photoconductivity In Amorphous Se-Ge-Ag System, R. S. Sharma, D. Kumar, A. Kumar Jan 2006

Transient Photoconductivity In Amorphous Se-Ge-Ag System, R. S. Sharma, D. Kumar, A. Kumar

Turkish Journal of Physics

Transient Photoconductivity measurements have been made in vacuum evaporated thin films of Se_{0.80 - x}Ge_{0.20}Ag_x at different intensities, temperatures and illumination times. The films exhibit long-lived residual photoconductivity, called persistent photoconductivity, with an extremely slow decay rate. The persistent photoconductivity (PPC) increases with an increase in intensity and illumination time. However, this quantity decreases with increase in temperature. These results indicate that the decay of photoconductivity is not only governed by the carrier trapped in the intrinsic defects but also gets affected by the light induced defect creation through structural changes The persistent photoconductivity effect is found to be suppressed …


Stagnation Point Flow And Heat Transfer Of A Micropolar Fluid In A Porous Medium, Hazem Ali Attia Jan 2006

Stagnation Point Flow And Heat Transfer Of A Micropolar Fluid In A Porous Medium, Hazem Ali Attia

Turkish Journal of Physics

The steady laminar flow in a porous medium of an incompressible non-Newtonian micropolar fluid impinging on a permeable flat plate with heat transfer is investigated. A numerical solution for the governing nonlinear momentum and energy equations is obtained. The effect of the porosity of the medium and the characteristics of the non-Newtonian fluid on both the flow and heat transfer is presented and discussed.


A Treatment Of A Higher-Order Singular Lagrangian As Fields System, N. I. Farahat, M. R. Heles Jan 2006

A Treatment Of A Higher-Order Singular Lagrangian As Fields System, N. I. Farahat, M. R. Heles

Turkish Journal of Physics

The higher-order singular Lagrangian system is treated as field system. Euler-Lagrange equations are solved with some constraints. An example is studied and a comparison with Hamiltonian formulation is done.


The Investigation Of Screening Of Chromoelectric And Chromomagnetic Fields In Noncovariant Gauges, Elşen Veli̇, Jale Yilmazkaya Süngü Jan 2006

The Investigation Of Screening Of Chromoelectric And Chromomagnetic Fields In Noncovariant Gauges, Elşen Veli̇, Jale Yilmazkaya Süngü

Turkish Journal of Physics

According to Thermal Quantum Chromodynamics (TQCD) hadron matter may exist in the form of quark-gluon plasma (QGP) at high temperatures and densities. The aim of the present work is to investigate the screening of chromoelectric and chromomagnetic fields in QGP in noncovariant gauges. In noncovariant gauges, gluon propagator has unphysical poles and singularities appear in the gluon self-energy diagram calculations. In this paper, we investigate gluon self-energy in lightcone and temporal gauges. In order to remove singularities, we use the Mandelstam-Leibbrandt prescription (ML prescription). We obtain that chromoelectric fields are screened, but chromomagnetic fields are not screened. In coordinate space, …


Investigation Of The Multipolarity Of Electromagnetic Transitions In ^{88,90}Kr Nuclei, Nuretti̇n Türkan, Davut Olgun, İhsan Uluer, Sai̇t İnan Jan 2006

Investigation Of The Multipolarity Of Electromagnetic Transitions In ^{88,90}Kr Nuclei, Nuretti̇n Türkan, Davut Olgun, İhsan Uluer, Sai̇t İnan

Turkish Journal of Physics

We have determined the most appropriate Hamiltonian that is needed for present calculations of nuclei about the A \cong 80 region by the view of Interacting Boson Model-2 (IBM-2). After obtaining the best Hamiltonian parameters, level energies and B(E2) probabilities of some transitions in ^{88,90}Kr nuclei were estimated. Results are compared with previous experimental and theoretical data and it is observed that they are in good agreement. Finally, R_1 = \frac{B(E2;4_1 \to 2_1)}{B(E2;2_1 \to 0_1)}, R_2 = \frac{B(E2;2_2 \to 2_1)}{B(E2;2_1 \to 0_1)}, \ R_3 = \frac{B(E2;0_2 \to 2_1)}{B(E2;2_1 \to 0_1)}, R_4 = \frac{{B(E2;2_2 \to 0_1)}{B(E2;2_2 \to 2_1)}, R_5 = \frac{B(E2;3_1 …


Peculiarities Of The Electric And Thermoelectric Properties Of Gate, M. M. Nassary Jan 2006

Peculiarities Of The Electric And Thermoelectric Properties Of Gate, M. M. Nassary

Turkish Journal of Physics

Measurements of electrical conductivity, Hall coefficient and thermoelectric power were carried out over the temperature range 136--563 K for GaTe compound grown in single crystal form by modified Bridgman technique. The crystals obtained had Positive-type conductivity with a hole concentration of 3.8 \times 10^{12} cm^{-3} at room temperature. Conductivity and Hall mobility at room temperature were evaluated as 4.4 \times 10^{-3} ohm^{-1} cm^{-1} and 7079 cm^2/V \cdot s, respectively. The energy gap width of 1.5 eV was found. The effective mass of holes and electrons at room temperature were 4.16 m_° and 0.1174 m_° , respectively


Rotating Disk Flow With Heat Transfer Of A Non Newtonian Fluid In Porous Medium, Hazem Ali Attia Jan 2006

Rotating Disk Flow With Heat Transfer Of A Non Newtonian Fluid In Porous Medium, Hazem Ali Attia

Turkish Journal of Physics

The steady flow of an incompressible viscous non-Newtonian fluid above an infinite rotating disk in a porous medium is studied with heat transfer. Numerical solutions of the nonlinear differential equations which govern the hydrodynamics and energy transfer are obtained. The effect of the porosity of the medium and the characteristics of the non-Newtonian fluid on the velocity and temperature distributions is considered.


Tunneling-Enhanced Recombination In Polycrystalline Cds/Cdte Solar Cells, Habi̇be Bayhan Jan 2006

Tunneling-Enhanced Recombination In Polycrystalline Cds/Cdte Solar Cells, Habi̇be Bayhan

Turkish Journal of Physics

The dominant dark current transport mechanism in as-grown and CdCl_2 processed CdS/CdTe heterojunction solar cells for temperatures below 300~K was investigated. The current-voltage properties of these solar cells is explained via tunnelling enhanced bulk and interface recombination models which give a quantitative description of the electronic loss mechanisms in the chalcopyrite-based heterojunction solar cells. The temperature dependence of the saturation current and the diode ideality factors of the as-grown and CdCl_2 processed CdTe solar cells are shown to be well described by this model.


Cherenkov Radiation In Homogeneous Isotropic Chiral Media, Pierre Hillion Jan 2006

Cherenkov Radiation In Homogeneous Isotropic Chiral Media, Pierre Hillion

Turkish Journal of Physics

We present a Fourier transform analysis of Cherenkov radiation for a point charge uniformly moving inside a 2D-homogeneous, isotropic, unbounded, chiral medium endowed with the Drude-Born-Fedorov constitutive relations when the chirality parameter ß and the wave number k make negligible the ß^2k^2 terms. The electromagnetic field is not described in terms of circularly right and left polarized waves but in terms of TM and TE components. The Cherenkov radiation arises when the velocity v of the point charge is greater than the phase velocity c/n, where n is the refractive index of the chiral medium and the electromagnetic field stands …


Assessment Of Wind Power Potential For Coastal Areas Of Pakistan, M. Akhlaque Ahmed, Firoz Ahmed, M. Wasim Akhtar Jan 2006

Assessment Of Wind Power Potential For Coastal Areas Of Pakistan, M. Akhlaque Ahmed, Firoz Ahmed, M. Wasim Akhtar

Turkish Journal of Physics

Selected coastal areas of Pakistan (Karachi, Ormara, Jivani and Pasni) were studied for the possibility of wind energy generation, using available meteorological data. Wind speed pattern, Extractable Wind power, Wind Energy and associated Weibull parameter for these coastal areas have been examined. The analysis also includes seasonal changes in wind speed values. The power output using fast and slow wind machines using different blade diameters have been estimated to explore the possible use for irrigation deep well pumping and small scale power generation. Along with this, 4 KW and 20 KW aero generators were also examined. It was found that, …


Ensemble Teleportation, Thomas Krüger Jan 2006

Ensemble Teleportation, Thomas Krüger

Turkish Journal of Physics

The possibility of teleportation is by sure the most interesting consequence of quantum non-separability. So far, however, teleportation schemes have been formulated by use of state vectors and considering individual entities only. In the present article the feasibility of teleportation is examined on the basis of the rigorous ensemble interpretation of quantum mechanics (not to be confused with a mere treatment of noisy EPR pairs) leading to results which are unexpected from the usual point of view.


Pendant ^{13}C Nmr Spectroscopy Applied To Ch_N Groups, Azmi̇ Gençten, İrfan Şaka, Sedat Gümüş Jan 2006

Pendant ^{13}C Nmr Spectroscopy Applied To Ch_N Groups, Azmi̇ Gençten, İrfan Şaka, Sedat Gümüş

Turkish Journal of Physics

Polarization enhancement nurtured during attached nucleus testing (PENDANT) NMR spectroscopy gives signals of quaternary carbon atoms in addition to signals indicative of CH, CH_2 and CH_3 groups. In this study, using product operator theory, analytical description of PENDANT NMR spectroscopy for CH_n (IS_n, I = 1/2, S = 1/2, n = 0, 1, 2, 3) spin systems are presented. Simulation and experimental results of PENDANT NMR spectroscopy are also presented. Theoretical results are found to be in exact agreement with the simulation results and in good agreement with the experimental ones.


Effect Of Thermal Annealing On The Band Gap And Optical Properties Of Chemical Bath Deposited Znse Thin Films, F. I. Ezema, A. B. C. Ekwealor, R. U. Osuji Jan 2006

Effect Of Thermal Annealing On The Band Gap And Optical Properties Of Chemical Bath Deposited Znse Thin Films, F. I. Ezema, A. B. C. Ekwealor, R. U. Osuji

Turkish Journal of Physics

Zinc selenide (ZnSe) thin films were deposited on glass substrate using the chemical bath deposition method at room temperature from aqueous solutions of zinc sulphate and sodium selenosulfate in which sodium hydroxide was employed as complexing agents. The `as-deposited' ZnSe thin films are red in color and annealed in oven at 473 K for 1 hour and on a hot plate in open air at 333 K for 5 minutes, affecting the morphological and optical properties. Optical properties such as absorption coefficient \alpha and extinction coefficient k, were determined using the absorbance and transmission measurement from Unico UV-2102 PC spectrophotometer, …


The Calculations Of Oscillator Strengths And Transition Probabilities For Atomic Fluorine, Gülteki̇n Çeli̇k, H. Şükür Kiliç, Erhan Akin Jan 2006

The Calculations Of Oscillator Strengths And Transition Probabilities For Atomic Fluorine, Gülteki̇n Çeli̇k, H. Şükür Kiliç, Erhan Akin

Turkish Journal of Physics

Oscillator strengths for transitions between individual lines belonging to some doublet and quartet terms, and multiplet transition probabilities of atomic fluorine have been calculated using weakest bound electron potential model theory (WBEPMT). In the determination of relevant parameters, we employed numerical non-relativistic Hartree-Fock (NRHF) wave functions for expectation values of radii and the necessary energy values have been taken from experimental energy data in the literature. Oscillator strengths and transition probabilities obtained in this work have been compared to experimental and theoretical values given in the literature.


Phase Distribution Of The Output Of Jaynes-Cummings Model With The Superposition Of Squeezed Displaced Fock States, Gamal Mohamed Abd Al-Kader Jan 2006

Phase Distribution Of The Output Of Jaynes-Cummings Model With The Superposition Of Squeezed Displaced Fock States, Gamal Mohamed Abd Al-Kader

Turkish Journal of Physics

The Wigner quasi-probability function for the superposition of squeezed displaced Fock states (SDFS's) is reviewed. The interaction of these states with a two-level atom in cavity with the presence of additional Kerr medium is studied. Exact general matrix elements of the time-dependent operators of a Jaynes-Cummings model (JCM), in the presence of a Kerr medium, with these states are derived. We have obtained the phase distribution by two different ways: one is by Pegg-Barnett formalism, the second is by integration of the Wigner function over the radial variable. Results of these two approaches are compared. The Wigner phase distributions for …


Modulated Photoconductivity Studies Of A-As_2se_3 Thin Films, Ruhi̇ Kaplan Jan 2006

Modulated Photoconductivity Studies Of A-As_2se_3 Thin Films, Ruhi̇ Kaplan

Turkish Journal of Physics

Modulated photocurrent measurements in amorphous arsenic triselenide (a-As_2Se_3) is reported. Particular focus is paid towards photocarrier lifetimes as a function of temperature, and applied electric field (i.e. dc) were determined by using the quadrature frequency-resolved spectroscopy method. The activation energy from the photocurrent as a function of temperature was determined to be about 125 meV for a constant illumination intensity of 2.3 mW. Its value was found to be almost independent of the applied electric field. The exponent \nu in the power law relationship (I_{ph} \propto G^v) between generating flux and photocurrent was obtained under different electric fields. The electric …


Electrical Switching Behaviour In Lead Phosphovanadate Glasses, B. Sujatha, C. Narayana Reddy Jan 2006

Electrical Switching Behaviour In Lead Phosphovanadate Glasses, B. Sujatha, C. Narayana Reddy

Turkish Journal of Physics

Electrical switching behaviour of lead phosphovanadate glasses were studied by determining the current-voltage characteristics. All the investigated glasses exhibit the dependence of threshold voltages on temperature, thickness and composition. Below holding current the I - V characteristics obey Ohms law followed by a negative resistance region where the bulk behaviour dominates and at higher values of current the samples goes to a low resistance state. The studied glasses exhibit memory type switching. It is suggested that the initial switching and channel formation are due to electronic, while thermal effects dominate in the formation of channels.


Dimensional Crossover In Semiconductor Structures: From 3d Electron Transport To Ballistic Electrons In 1d, Karl-Fredrick Berggren Jan 2006

Dimensional Crossover In Semiconductor Structures: From 3d Electron Transport To Ballistic Electrons In 1d, Karl-Fredrick Berggren

Turkish Journal of Physics

Modern semiconductor technologies have made possible special devices in which a gradual dimensional crossover may be induced by means of applied electric fields. Two specific examples are described. The first one is a special GaAs field effect transistor in which the thickness of the active electron gas layer may be varied by external voltages. With decreasing layer thickness transverse states become quantized and by depopulating the corresponding subbands a tunable dimensional crossover from 3D to 2D is achieved. The second example describes how a 2D to 1D crossover may be obtained in high-mobility split-gate GaAs/AlGaAs heterostructures. Effects of interactions in …


Self-Assembled Nano-Structures On The Icosahedral Al-Pd-Mn Quasicrystal, Mehmet Erbudak, Jean-Nicolas Longchamp, Yves Weisskopf Jan 2006

Self-Assembled Nano-Structures On The Icosahedral Al-Pd-Mn Quasicrystal, Mehmet Erbudak, Jean-Nicolas Longchamp, Yves Weisskopf

Turkish Journal of Physics

A quasicrystal is a solid with an aperiodic atomic distribution, but displaying discrete diffraction pattern. At an interface where an ordinary crystal and a quasicrystal intersect, the lack of commensurability between the structures leads to misfits on atomic scale resulting in a wealth of novelties. Here, we present experimental observations on three essentially different cases: Al, Fe, and Si ultra-thin layers grown in vacuum on the pentagonal surface of an icosahedral Al-Pd-Mn quasicrystal. In all three cases, the growing layer decays into nm-size islands. Al is the major alloy component of the substrate material and provides a natural tool to …