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Near Bandedge Optical Absorption Processes In Semi Insulating And N-Type Gaas, Tacetti̇n Yildirim, Sebahatti̇n Tüzemen, Seydi̇ Doğan, Beki̇r Gürbulak, Aytunç Ateş, Muhammet Yildirim
Near Bandedge Optical Absorption Processes In Semi Insulating And N-Type Gaas, Tacetti̇n Yildirim, Sebahatti̇n Tüzemen, Seydi̇ Doğan, Beki̇r Gürbulak, Aytunç Ateş, Muhammet Yildirim
Turkish Journal of Physics
Near bandedge optical absorption processes in semi-insulating (SI) GaAs and Te-doped n-type GaAs crystals were investigated in the temperature range 10--300 K. We observed absorption peaks whose maximum energies E_{m}, ranging from 1.498 to 1.485 eV decrease as the temperature increases from 10 K to 100 K. The peaks for both SI and n-type GaAs disappeared above 100 K. Extrapolating the graphs of E$_{g}-E_{m} versus temperature, we observed that near bandedge absorption is overlapped by the conduction band at about 220 K and 260 K for n-type and SI samples, respectively. Furthermore, we demonstrated that the absorption in the region …
Schrödinger Quantization And Excited States Of Zitterbewegung, Selahatti̇n Gönen, Ali̇ Havare
Schrödinger Quantization And Excited States Of Zitterbewegung, Selahatti̇n Gönen, Ali̇ Havare
Turkish Journal of Physics
General wavefunction is expanded as power series of a variable which describes internal dynamics of particle, to show that it contains excited states of Schrödinger's Zitterbewegung.
Kinetics Of Light-Induced Metastable Defect Creation And Annealing In A-Si:H, Alp Osman Kodolbaş, Aynur Eray, Özcan Öktü
Kinetics Of Light-Induced Metastable Defect Creation And Annealing In A-Si:H, Alp Osman Kodolbaş, Aynur Eray, Özcan Öktü
Turkish Journal of Physics
Constant Photocurrent Method (CPM) and steady state photoconductivity measurements are used to investigate the creation of light-induced metastable defects in a-Si:H at room temperature and their annealing. Light-induced metastable defect concentration N$_{d}$ varies with exposure time t_{e}as t_{e}^{r} with r=0.34\ pm 0.02, as expected from the recombination induced weak bond breaking model [1]. The validity of a stretched exponential model is also studied [2]. From the annealing experiments, the distribution of thermal annealing activation energies is calculated following the method proposed by Hata and Wagner [3]. Defects created at room temperature show a narrow distribution of annealing activation energies peaking …
The Contributions Of Anomalous Magnetic Moment To Relativistic Landau Orbits, Ali̇ Havare, Nuri̇ Ünal
The Contributions Of Anomalous Magnetic Moment To Relativistic Landau Orbits, Ali̇ Havare, Nuri̇ Ünal
Turkish Journal of Physics
In this work, the contributions of anomalous magnetic moment to relativistic Landau orbits are calculated by the method of self-field quantum electrodynamics. In addition to contributions from positive energy states new terms from negative energy states that have not been taken into account before are now also included. Contributions from these terms are found to be in the same order as positive terms.
The Determination Of Thermal Annealing Effect On A-Si:H Films Coated On Glass And On Single Crystalline Of Silicon, Necmi̇ Seri̇n, Tülay Seri̇n, Ali̇ Riza Özdemi̇r, Bora Alkan, Çeli̇k Tarimci, Basri̇ Ünal
The Determination Of Thermal Annealing Effect On A-Si:H Films Coated On Glass And On Single Crystalline Of Silicon, Necmi̇ Seri̇n, Tülay Seri̇n, Ali̇ Riza Özdemi̇r, Bora Alkan, Çeli̇k Tarimci, Basri̇ Ünal
Turkish Journal of Physics
The aim of this study was to examine the effect of thermal annealing on hydrogenated intrinsic amorphous silicon a-Si:H films. Hydrogenated intrinsic amorphous films were seperately coated on glass and single cyrstalline silicon substrates by means of d.c. magnetron sputtering technique. a-Si:H/glass and a-Si:H/c-Si samples were annealed in the temperature range of 23-250^oC, 23-200^oC and 600-1050^oC, respectively. The effect of annealing on the a-Si:H films were examined by means of Infrared vibrational transmittance spectrum technique (IR) in the wavenumber range 4000-400 cm^{-1} and Scanning Electron Microsope (SEM). The results were interpreted in terms of hydrogen diffusion.
Preparation And Anisotropic Elastic Property Of Bi-Sr-Ca-Cu-O Whiskers, Khaliq A. Chaudhary, M. Arshad Choudhry
Preparation And Anisotropic Elastic Property Of Bi-Sr-Ca-Cu-O Whiskers, Khaliq A. Chaudhary, M. Arshad Choudhry
Turkish Journal of Physics
Flexible and superconducting Bi-Sr-Ca-Cu-O whiskers have been prepared by sintering the melt-quenched glassy powder at 830^oC in oxygen atmosphere. X-ray diffraction and a.c. susceptibility measurements reveal that the whiskers belong to 2212 phase with T_{c} = 79k. The whiskers possess high strength and flexibility along c-axis but were found to be weak and brittle when bent normal to the c-axis. The anisotropic micromechanical elastic property of the whiskers have been demonstrated under a low power optical microscope.
Filamentation Of Light Emission In An Infrared-Visible Image Converter With A Semiconductor Photodetector, Hi̇lal Yücel Kurt, H. S. Kiymaz, B. G. Salamov, K. Çolakoğlu
Filamentation Of Light Emission In An Infrared-Visible Image Converter With A Semiconductor Photodetector, Hi̇lal Yücel Kurt, H. S. Kiymaz, B. G. Salamov, K. Çolakoğlu
Turkish Journal of Physics
This work studies the light emission patterns associated with the spatial modulation of the transversal distribution of the current density in a converter cell with a GaAs semiconductor cathode. Such light emission exhibits spatial structures of current filaments depending on the feeding voltage, illumination intensity, gas pressure and the surface treatment of the electrodes. When the current is increased above the stable limit, breakdown or small current filamentations begin. However, n-GaAs exhibits an S-shaped current-density-field relation due to impact ionization of carriers from shallow donors into the conduction band under high electric fields. The assessment of the filament formation is …
Temperature Dependence Of Galvanomagnetic Properties For Lightly Doped N-Type Si, Aytunç Ateş, Beki̇r Gürbulak, Seydi̇ Doğan, Muhammet Yildirim, Sebahatti̇n Tüzemen
Temperature Dependence Of Galvanomagnetic Properties For Lightly Doped N-Type Si, Aytunç Ateş, Beki̇r Gürbulak, Seydi̇ Doğan, Muhammet Yildirim, Sebahatti̇n Tüzemen
Turkish Journal of Physics
The temperature dependence of Hall and magnetoresistance effects in n-type Si having a resistivity of 1400 {\Omega } cm at room temperature is studied in the temperature range of 210-320 K. The variation of transverse magnetoresistance as a function of temperature is similar to the longitudinal magnetoresistance variation in < 001 > and < 1\bar {1}0 > n-Si the samples. It is observed that, in < 001 > sample, the transverse and longitudinal magnetoresistance variation is greater than that in the < 1\bar {1}0 > sample. In both samples, the temperature dependences of magnetoresistance is in accordance to double space anisotropy parameters. In both samples, the transverse and longitudinal magnetoresistance coefficents increase with increasing …
A Method For Identifying Gluon Jets With High Purity In 3-Jet Hadronic Z Decays, Ayda Beddall
A Method For Identifying Gluon Jets With High Purity In 3-Jet Hadronic Z Decays, Ayda Beddall
Turkish Journal of Physics
A method for identifying gluon jets with very high purity is presented and the performance evaluated. Quark and gluon jets from Monte Carlo simulated Hadronic Z decays are identified by energy ordered jets and applying heavy flavour tagging. It is shown that quark and gluon jets can be identified with a purity of about 98%.
Dependence Of Neutron-Proton Entity Transfer On Superfluid Parameters, Hüseyi̇n Ayteki̇n
Dependence Of Neutron-Proton Entity Transfer On Superfluid Parameters, Hüseyi̇n Ayteki̇n
Turkish Journal of Physics
In this study the nuclear matrix elements of neutron-proton (n-p) entity transfer of even-even nuclei are investigated in the Tamm-Dancoff Approximation (TDA). These matrix elements are used for n-p entity stripping from even-even nuclei and n-p entity absorbing of even-even nuclei. It is shown that the matrix element of 0^{+} \to 0^{+} transition between {\left {Z,N} \right\rangle} and {\left {Z - 2,N - 2} \right\rangle} even-even nuclei via the 1^{+} states of {\left {Z - 1,N - 1} \right\rangle} intermediate nuclei depends only on the superfluid parameters.
The Investigation Of The E2/M1 Multipole Mixing Ratios And Deformation Parameters Of Electromagnetic Transitions In Decay Of ^{156}Gd, Mehmet Baylan, İhsan Uluer
The Investigation Of The E2/M1 Multipole Mixing Ratios And Deformation Parameters Of Electromagnetic Transitions In Decay Of ^{156}Gd, Mehmet Baylan, İhsan Uluer
Turkish Journal of Physics
The extended Rotation -- Vibration Model (RTV) containing different deformations for protons and neutrons is applied to ^{156}Gd nucleus. Using the Rotation-Vibration Model approach multipole mixing ratios \delta (E2/M1), deformation parameter \beta_{o} , g_{R} factors, and quadrupole moments q_{2} + and q_{o} were calculated.
Micro-Crystallographic, Optical And Transport Studies Of Cd_{0.7} Zn_{0.3} Se : Sb Thin Films, D. S. Sutrave, G. S. Shahane, V. B. Patil, L. P. Deshmukh, B. D. Sarwade
Micro-Crystallographic, Optical And Transport Studies Of Cd_{0.7} Zn_{0.3} Se : Sb Thin Films, D. S. Sutrave, G. S. Shahane, V. B. Patil, L. P. Deshmukh, B. D. Sarwade
Turkish Journal of Physics
Cd_{1-x}Zn_{x}Se thin film structures doped with various concentrations of trivalent antimony were chemically deposited onto glass-substrates. These structures were then characterised through the XRD, SEM, optical and electrical characterization techniques. The X-ray diffractograms of both as-prepared and Sb-doped samples were obtained and analysed. The analysis revealed that the samples are microcrystalline over the whole range of the doping concentration (0 to 2 mol %). It is striking that the intensities of hexagonal and cubic reflections of CdSe went on increasing with doping concentration upto 0.1 mol % and decreased with further increase in Sb^{3+} content in the film whereas peak …
Effect Of The Zn Concentration On The Characteristic Parameters Of Zn_{X}Cd_{1 - X}S Thin Films Developed By Spraying Pyrolysis Method Under The Nitrogen Atmosphere, Meti̇n Bedi̇r, Refi̇k Kayali, Mustafa Öztaş
Effect Of The Zn Concentration On The Characteristic Parameters Of Zn_{X}Cd_{1 - X}S Thin Films Developed By Spraying Pyrolysis Method Under The Nitrogen Atmosphere, Meti̇n Bedi̇r, Refi̇k Kayali, Mustafa Öztaş
Turkish Journal of Physics
The electronic and optical properties of Zn_{x}Cd _{(1- x)}S thin films (0.0 \le x \le 0.7) fabricated using the chemical spray method have been investigated in nitrogen atmosphere. The films are deposited on glass substrates at 420^oC substrate temperature. The related optical data are recorded in the wavelength range 200-700 nm. In addition, the absorption coefficient is determined and correlated with the photon energy in order to estimate the direct transition energy bandgap. The crystallite size and degree of preferential orientation were found to decrease with the increase of x and to improve upon annealing in vacuum at \cong 600^oC. …
Urbach's Rule And Optical Properties For Tlgas_{2}, Aytunç Ateş, Beki̇r Gürbulak, Muhammet Yildirim, Seydi̇ Doğan, Songül Duman, Tacetti̇n Yildirim, Sebahatti̇n Tüzemen
Urbach's Rule And Optical Properties For Tlgas_{2}, Aytunç Ateş, Beki̇r Gürbulak, Muhammet Yildirim, Seydi̇ Doğan, Songül Duman, Tacetti̇n Yildirim, Sebahatti̇n Tüzemen
Turkish Journal of Physics
Absorption measurements were carried out on TlGaS_{2} sample in the temperature range between 10 and 320 K in 10 K steps. There is an abrupt change in the Urbach energy at 180 K and 280 K and steepness parameter at 120 K and 220 K .Obtained from the changing of the Urbach energy, these may be phase transition temperatures. The phonon energies calculated for TlGaS_{2} is 19.7 \pm 5 meV.
On Numerical Simulations Of Composite Dielectrics In Thermally Stimulated Conditions, Eni̇s Tuncer, Stanislaw M. Gubanski
On Numerical Simulations Of Composite Dielectrics In Thermally Stimulated Conditions, Eni̇s Tuncer, Stanislaw M. Gubanski
Turkish Journal of Physics
A binary composite system with particulated inclusions was considered. First, thermally stimulated depolarization ({\sc tsd}) currents of the system were simulated by altering different parameters of the {\sc tsd} current equation, {\em i.e.}, intrinsic dielectric properties of constituents, conductivity of inclusions, heating rate and activation energy of inclusion conductivity and shape of inclusions. Two different methods of finding the activation energy of {\sc tsd} processes from the simulated {\sc tsd} currents were discussed. Second, we have included the Monte Carlo technique by assuming that the shape factor of inclusions were distributed. These simulations have shown that if the inclusions were …
Spin Polarized Cold And Hot Dense Neutron Matter, S. A. Moharrm, Azza O. El-Shal
Spin Polarized Cold And Hot Dense Neutron Matter, S. A. Moharrm, Azza O. El-Shal
Turkish Journal of Physics
The Thomas-Fermi (TF) model is used to calculate the equation of state of thermal polarized neutron matter. The properties of cold and hot neutron matter have been investigated. A realistic density-dependent M3Y effective nucleon-nucleon (NN) interaction where the Yukawa strengthes are based on the G-matrix of the Paris interaction has been used. Special attention is devoted to the effect of the spin excess parameter on these properties. Moreover, the effect of some realistic density dependence has been studied. The results obtained are in reasonable agreement with previous theoretical estimates using different methods of calculation.
Radiation Transfer For Exponential C(X), Fatma Erdoğan
Radiation Transfer For Exponential C(X), Fatma Erdoğan
Turkish Journal of Physics
The emergent flux for radiation transfer in inhomogeneous half-space for exponential c(x) = 1 + ke^{-mx}/1 + be^{-mx} is obtained by using Modified-Eddington method, where m, b, k are constants. As a result of this work, angular flux is obtained in terms of Jacobi polynomials.
Radial And Nonradial Oscillations Of 63 Her (Hd155514 = Hr6391), Ri̇kkat Ci̇velek, Ni̇lgün Kiziloğlu, Hali̇l Kirbiyik
Radial And Nonradial Oscillations Of 63 Her (Hd155514 = Hr6391), Ri̇kkat Ci̇velek, Ni̇lgün Kiziloğlu, Hali̇l Kirbiyik
Turkish Journal of Physics
An attempt has been made toward explaining the observed frequencies in 63 Her. A sequence of evolutionary models have been calculated up to a point where stellar parameters match the observed luminosity and effective temperature of 63 Her. Radial and nonradial oscillations frequencies were obtained for a series of masses 1.85, 1.90 and 1.95 M_\odot and eigth models which represent best the pulsations of 63 Her are given in this paper. Calculations are restricted to low harmonic degrees ( l= 0,1,2,3 ). Six of the eigth observed frequencies quoted in literature were obtained. These we obtained for the model of …
Tsl-Epr Correlation Study Of Lapo_4 : Ce, Tb, B. S. Chakrabarty, K. V. R. Murthy, T. R. Joshi
Tsl-Epr Correlation Study Of Lapo_4 : Ce, Tb, B. S. Chakrabarty, K. V. R. Murthy, T. R. Joshi
Turkish Journal of Physics
Gamma irradiated TSL glow curves of laboratory made phosphor samples of LaPO_{4}:Ce, Tb exhibited one intense peak around 408 K and two smaller peaks around 508 K and 613 K. The spectrum of the first glow peak gives spectral peaks around 480 nm and 540 nm, which can be attributed to the thermal destruction of F^{++} centres and PO_4^{2-} radicals. The luminescense centre has been thought to be Cerium and Terbium ions. The glow peak around 413 K for UV irradiated samples has been attributed to aggregates of dopant ions. The photoluminescence study of the samples exhibited one intense peak …
Structural Analysis Of A Gaas/Al_Xga_{1-X} As Hot Electron Light Emitter Using Double Axis X-Ray Diffraction, Ali̇ Teke
Turkish Journal of Physics
We report on interference peaks in double axis x-ray rocking curves of tunable wavelength hot electron light emitters. The device is based on a p-GaAs and n-Ga_{1-x}Al_xAs heterojunction containing an inversion layer on the p- side, and GaAs quantum wells on the n- side of the junction, a construction known as HELLISH-2 (Hot Electron Light Emitting and Lasing in Semiconductor Heterostructure-Type 2). The interference has been shown to strongly depend on the periodicy of the device structure. Experimental curves are compared with simulated rocking curves. Some structural parameters, such as total epilayer thickness, composition ratio and quantum well width and …
The Electron-Photon Coincidence Method And Its Application To Excitation Of The 2p State Of Atomic Hydrogen, Hüseyi̇n Ali̇ Yalim, Albert Crowe
The Electron-Photon Coincidence Method And Its Application To Excitation Of The 2p State Of Atomic Hydrogen, Hüseyi̇n Ali̇ Yalim, Albert Crowe
Turkish Journal of Physics
Early measurements of atomic excitation by electron scattering observed either the scattered electron or decay photon. An excited state can not be completely defined by such experiments due to loss of information. Therefore a new method was developed in the early 70's called the correlation method. The new correlation method involves the detection of both the scattered electron and photon arising from the same collision using coincidence techniques. This method enables a full description of an excited state. In this paper, we give a discussion of to the method and its application to excitation of the 2p state of atomic …
A Quadratic Boundary Element Formulation For Neutron Diffusion Equation, Bi̇lge Özgener, Havar Isikli
A Quadratic Boundary Element Formulation For Neutron Diffusion Equation, Bi̇lge Özgener, Havar Isikli
Turkish Journal of Physics
The boundary element method (BEM) is a technique based on the principle of the conversion of the governing differential equation to the boundary integral equation with consequent reduction by one in the dimension of the problem. In this work, quadratic boundary elements and thus BEM have been applied to neutron diffusion calculations to render the treatment of curved boundaries possible. The results of the developed computer program BENDQ has been compared to the analytical solutions and validated.
Contribution To The Relationship Between Solar Radiation And Sunshine Duration In The Tropics: A Case Study Of Experimental Data At Ilorin, Nigeria, Sunday O. Udo
Turkish Journal of Physics
From monthly average daily values of clearness index and relative sunshine spanning a period of two years, two equations (linear and quadratic) of the Angstrom-Prescott model have been developed for the estimation of global solar irradiation at Ilorin (Lat. 8°32'N, Long. 4°34'E), a tropical location. Comparison of the regression coefficients of the linear type model showed that the values are quite consistent with those quoted in the literature for the Tropics. The predictive efficiencies of these two models are also compared with those which are believed to be applicable globally, and those developed for the Nigerian environment. Although some of …
Short-Range Correlations In Coupled Quantum-Wire Systems, A. Yurtsever, B. Tanatar
Short-Range Correlations In Coupled Quantum-Wire Systems, A. Yurtsever, B. Tanatar
Turkish Journal of Physics
We study the contact values of the inter-wire pair-correlation function in electron-electron and electron-hole double-wire systems. For this purpose the ladder approximation as generalized to multicomponent systems is used. The ladder approximation yields positive values for the inter-wire g_{ee}(0) and g_{eh}(0) for all values of the density parameter r_s and distance d between the wires. This allows us to infer possible instabilities in the system more reliably compared to other approaches. We also investigate the effects of quantum-wire width and screening on the inter-wire pair-correlation functions. PACS numbers: 05.30.Fk, 73.20.Dx, 71.45.Gm, 73.40.Kp
Excess Properties Of Alcohol - Water Systems At 298.15 K, Hülya Yilmaz
Excess Properties Of Alcohol - Water Systems At 298.15 K, Hülya Yilmaz
Turkish Journal of Physics
Dielectric constants \varepsilon, viscosities \eta, refractive indices n and densities d have been measured over the entire mole fraction range for the water - methyl, ethyl, n-propyl alcohol binary systems at 298.15 K. From the experimental data excess dielectric constants \varepsilon^E, excess viscosities \eta^E and Kirkwood correlation factors g_k have been calculated and studied. Their behaviour suggests the existence of intermolecular interactions and plotted curves show that excess dielectric constant and g_k values decrease with the increasing of carbon atom number, while excess viscosity increases.
On The Numerical Solution And Limitations Of Energy Equation For Vertical Bridgman System With Varying Temperature Gradient At The Boundary, Ergün Taşarkuyu, Evren Akar, Bülent Gülteki̇n Akinoğlu
On The Numerical Solution And Limitations Of Energy Equation For Vertical Bridgman System With Varying Temperature Gradient At The Boundary, Ergün Taşarkuyu, Evren Akar, Bülent Gülteki̇n Akinoğlu
Turkish Journal of Physics
In vertical Bridgman crystal growth systems solid-liquid interface shape is one of the most important factors affecting the product quality. Most of the theoretical studies to determine the interface shape consider the numerical solution to the heat-conduction and the energy equation. The purpose of this work is to present and discuss a numerical solution to the energy equation (also called the convection-diffusion equation) for a vertical Bridgman system with varying temperature gradient at the boundary. Different system parameters are examined and the importance of the pulling rate for different materials in the utilization of the energy equation is emphasized. The …
Off-Diagonal Matrix Elements And Sum Rules Involving Coulomb And Isotropic Oscillator Functions, Harry A. Mavromatis
Off-Diagonal Matrix Elements And Sum Rules Involving Coulomb And Isotropic Oscillator Functions, Harry A. Mavromatis
Turkish Journal of Physics
Off-diagonal matrix elements and sum rules for the Coulomb and isotropic oscillator systems are obtained from a study of relations between the off-diagonal matrix elements of a general recursion relation.