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Articles 2521 - 2550 of 2713

Full-Text Articles in Physics

Relativistic Electron In The Field Of Two Coulomb Centers, V.I. Matveev, D.U. Matrasulov, Kh. Yu. Rakhimov Jan 1998

Relativistic Electron In The Field Of Two Coulomb Centers, V.I. Matveev, D.U. Matrasulov, Kh. Yu. Rakhimov

Turkish Journal of Physics

Ground state wave function and the energy term of the relativistic electron moving in the field of two Coulomb centers are calculated analytically by the method of linear combination of atomic orbitals. Obtained analytical formula is applied to the calculation of the critical distance between two heavy nuclei at which energy term reaches the boundary of the lower continuum.

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On The One-Loop Yukowa Coupling Beta Function To Order Yg^2 In A General \Alpha Gauge And Its Gauge Indepence, M. Özer Jan 1998

On The One-Loop Yukowa Coupling Beta Function To Order Yg^2 In A General \Alpha Gauge And Its Gauge Indepence, M. Özer

Turkish Journal of Physics

We present the calculation of the one-loop Yukawa coupling beta function to order $Yg^2$ in a general $\alpha$ gauge, where $Y$ and $g$ are Yukawa and gauge couplings. We show explicitly how the gauge parameter $\alpha$ cancels out from the beta - function and demonstrate how some familiar results are obtained from it.

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The Milne And The Constant Source Problems For The Fbis Kernel, M.Ç .. Güleçyüz, A. Kaşkaş Jan 1998

The Milne And The Constant Source Problems For The Fbis Kernel, M.Ç .. Güleçyüz, A. Kaşkaş

Turkish Journal of Physics

Transport solutions to the monoenergetic constant source and the Milne problems for the forward-backward-isotropic scattering (FBIS) kernel are obtained by method of singular expansion modes. The monoenergetic linear transport equation for extremely anisotropic scattering with constant source is reduced to a transport equation with isotropic scattering. The expansion coefficient is obtained in a form involving exact integral equations and determined by the accompanying new boundary conditions and the half-range orthogonality relations. In the zeroth order approximation, the analytical expressions for neutron density and the emergent angular distributions are also obtained as a function of forward scattering.

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Topics On The Physics Potential And Detector Aspects Of The Lc-Hera Ep Collider, A. De Roeck Jan 1998

Topics On The Physics Potential And Detector Aspects Of The Lc-Hera Ep Collider, A. De Roeck

Turkish Journal of Physics

We present a brief account of some physics topics which could be addressed at a collider consisting of the HERA proton ring and the future $e^+e^-$ Linear Collider. A few experimental aspects are also discussed.

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Physics At Future Ep, \Gammap (Linac-Ring) And \Mup Colliders, Ilya F. Ginzburg Jan 1998

Physics At Future Ep, \Gammap (Linac-Ring) And \Mup Colliders, Ilya F. Ginzburg

Turkish Journal of Physics

The physical problems for the enumerated colliders are discussed. It is taken into account that all these machines can work only after corresponding parental colliders.

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Some Physical Problems For Photon Colliders, Ilya F. Ginzburg Jan 1998

Some Physical Problems For Photon Colliders, Ilya F. Ginzburg

Turkish Journal of Physics

Higgs hunting at different colliders is discussed with new possibilities related to photon colliders are discussed. Brief review of discovery potential for new physics is presented.

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Physics At Hera+Lc Based \Gammap Colliders, Z. Z. Aydin Jan 1998

Physics At Hera+Lc Based \Gammap Colliders, Z. Z. Aydin

Turkish Journal of Physics

In this proceeding I discuss the proposal of constructing a $\gamma p$ collider at DESY based on a Linac-Ring type $ep$ machine, the HERA+LC. A high energy $\gamma$ beam for this collider is produced by the Compton back-scattering of laser photons off the electron beam from the linear accelerator. Using the parameters of the proton ring of HERA and those of the proposed linear $e^{+}e^{-}$ colliders (LC, specifically TESLA, CLIC or Linac1) we expect a luminosity of $L_{\gamma p} =(1-2)\times 10^{31} cm^{-2} s^{-1}$, due to a reasonable improvement of the proton beam. We examine the physics research program for the …

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Analysis Of Atmospheric Concentrations Of Radon And Thoron Using Beta Counting Technique, G. S. Islam, S. M. Basunia Jan 1998

Analysis Of Atmospheric Concentrations Of Radon And Thoron Using Beta Counting Technique, G. S. Islam, S. M. Basunia

Turkish Journal of Physics

This paper presents a detailed theory and experimental procedure for measurement and analysis of mixed radon and thoron in the environment. The technique has been successfully applied to the study of seasonal variations of radon and thoron in the atmosphere around Rajshahi, Banladesh, during the years 1989-1991. The maximum radon concentration in outdoor air was observed in the winter from December to January while the indoor radon concentration was found to be maximum during the monsoon months of July and August. The implication of the results is briefly discussed in the paper.

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A Study Of Heavy-Ion Elastic Scattering Reactions Using A Semimicroscopic Model, A. A. Farra Jan 1998

A Study Of Heavy-Ion Elastic Scattering Reactions Using A Semimicroscopic Model, A. A. Farra

Turkish Journal of Physics

The differential cross sections for elastic scattering of ^{16}O from ^{20}Ne have been calculated using an optical potential and distorted wave Born approximation (DWBA) calculations. In the present calculations several prescriptions were tried in the ion-ion potential. The DWBA calculations were performed employing folded real and Woods-Saxon optical potentials for the distorted waves. Inclusion of the exchange process explains the large back-angle cross sections. The elastic scattering differential cross sections are successfully described by calculations in which elastic alpha-transfer amplitudes are coherently added to direct elastic scattering amplitudes.

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Effect Of Deposition Conditions On Composition Of Rf-Sputtered Bi-Sr-Ca-Cu-O Thin Films, Ayhan Güldeste Jan 1998

Effect Of Deposition Conditions On Composition Of Rf-Sputtered Bi-Sr-Ca-Cu-O Thin Films, Ayhan Güldeste

Turkish Journal of Physics

The effect of rf-magnetron sputtering conditions on as-deposited film composition using a stoichiometric Bi_2Sr_2CaCu_2O_y (Bi-2212) target was investigated in an on-axis configuration, as the stoichiometrical control of the film is the most important parameter for the proper study of film characteristics. It was found that substrate target distance up to 55-60 mm may provide a film composition close to the target composition. The sputtering chamber pressure effecting film composition, especially in respect of Bi, is an important parameter which needs very pracise control. Bi ratio in the deposited films increases with increasing Ar pressure while Sr and Ca are not …

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Optical Anisotropy Of Iron Garnets With Growing Anisotropy, Odil Ochilov Jan 1998

Optical Anisotropy Of Iron Garnets With Growing Anisotropy, Odil Ochilov

Turkish Journal of Physics

The theoretical analysis of the position of principal diachronic directions at magnetization rotation in (100) and (110) planes for the case of growing dichroism axes in random directions was made. The calculations of angular dependencies of dichroic axes (DA) position for different values of the magneto-optical anisotropy parameter, a, have been done. The relations between the growing and magneto-optical dichroism, K/M, and the angle \delta characterizing the direction of principal growing dichroism axes were given. The angular dependences of DA position in epitaxial iron garnet films have been investigated experimentally. The measurements at the different light wavelengths permitted one to …

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Interrelation Of Magnetic Properties With The Crystal Structures Of Mefese (Me = Ti; V; Cr; Fe; Co; Ni) Compounds, R. Sadikhov, A. Namazov, J. Guseinov Jan 1998

Interrelation Of Magnetic Properties With The Crystal Structures Of Mefese (Me = Ti; V; Cr; Fe; Co; Ni) Compounds, R. Sadikhov, A. Namazov, J. Guseinov

Turkish Journal of Physics

Magnetization of MeFe$_2$Se$_4$ (Me = Ti; V; Cr; Fe; Co; Ni) compounds at low temperatures has been investigated. It is shown that these compounds are ferrimagnetics with low values of specific magnetization. It is established that along the crystal axis $c$ of a given compound, there have been carried out two types of exchange interactions; cation-cation and cation-anion-cation with different dependence of their quantity on interatomic distance.

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Deformation Methods For Investigation Of The Deep Level Parameters In Semiconductors, S. Z. Zainabidinov, A. Abduraimov, O. O. Mamatkarimov, I.G. Tursunov, R.Kh. Khamidov Jan 1998

Deformation Methods For Investigation Of The Deep Level Parameters In Semiconductors, S. Z. Zainabidinov, A. Abduraimov, O. O. Mamatkarimov, I.G. Tursunov, R.Kh. Khamidov

Turkish Journal of Physics

In this paper deformation methods are offered to investigate deep level parameters in semiconductors. It is based on strain parameters measurements of compensated and overcompensated semiconductors. The dynamic changes of current flow in compensated and overcompensated samples of $p$-type $Si: Ni$ and $n$-type $Si: Mn$ under uniform pulse hydrostatic compression (UHC) was investigated. It was observed that in $p$-type $Si: Ni$ samples ionization energy levels $Ni$ at UHC increases, on the contrary in samples $n$-type $Si: Mn$ it decreases. The ionization energy and baric coefficient of the shift of $Ni$ and $Mn$ levels were bounded.

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Modelling Of Radiation Regime Receiver Cavities Of Solar Power Plants, Eduard Avanesov, Nina Berezhnaya Jan 1998

Modelling Of Radiation Regime Receiver Cavities Of Solar Power Plants, Eduard Avanesov, Nina Berezhnaya

Turkish Journal of Physics

In this work, we develop a model for radiant heat transfer calculations inside spherical and cylindrical spaces. The analysis of the possibility of mirror cone subreflector applications for uniform flux density attainment is carried out. A procedure optimizing equiilluminate space forming a search for an indicatrix's composition is developed.

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Electro-Optic Response Of A Polymer Dispersed Liquid Crystal Film, Rıdvan Karapinar Jan 1998

Electro-Optic Response Of A Polymer Dispersed Liquid Crystal Film, Rıdvan Karapinar

Turkish Journal of Physics

Polymer dispersed liquid crystal (PDLC) films are potentially useful in electro-optic devices since they can be used for vision products. In this work the PDLC thin films were prepared by a photopolymerization induced phase separation method and electro-optic properties of the films were investigated.

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The Influence Of The Dispersion Of Boron Silicate On The Migration Of Non-Equilibrium Charge Carriers Generated By Eect Of An Electric Discharge, A.M. Hasanov Jan 1998

The Influence Of The Dispersion Of Boron Silicate On The Migration Of Non-Equilibrium Charge Carriers Generated By Eect Of An Electric Discharge, A.M. Hasanov

Turkish Journal of Physics

ESR was used in an investigation of the influence of Boron Silicate dispersion on the accumulation of paramagnetic centers (PC). It was observed that the rate of accumulation of PC increase by increasing of the grain size (r). At $r < 0.08$ mm the electrons ($F^+$-centers) are localized on the surface and with increasing grain size up to $0.08 < r < 0.22$ mm charge stratification takes place, the electrons are distributed in near-surface layer and the holes ($V$-centers) are localized in the bulk of the insulator. It was established that the transport of non-equilibrium charge carriers (NCC) from the bulk to the surface of Boron Silicate was due to a drift from the depth $(d \sim 10 \mu m)$ to a bulk-charge field generated by an electric discharge. The value of the surface field $E_s \sim 10^5 V/cm$ is determined by experimental results of the data. The kinetics of the isothermal annealing (300 K) are used to establish the influence of the surface field on the annihilation of NCC in the ''dead'' layer of separated charges.

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The Effect Of Halogen Impurities On Electrocunductivity Of Chalcogenide Glass Semicunductor Se-As System, A.I. Isaogli, S.M. Ibrahimgizi, A.R. Kamilogli Jan 1998

The Effect Of Halogen Impurities On Electrocunductivity Of Chalcogenide Glass Semicunductor Se-As System, A.I. Isaogli, S.M. Ibrahimgizi, A.R. Kamilogli

Turkish Journal of Physics

DC conductivity has been measured as function of dopant concentration for Se-As glass containing 2-10 \% As, doped with Cl or Br. It was established that concentration dependences of the conductivity have maxima for concentration of Cl or Br between $10^{-3}$ and $10^{-2}$ at \%. The effect of halogen impurities on electroconductivity of Se-As glasses has been attributed to the change of relative concentrations of the charged defect centers $(C^-_1, C^+_3)$ and to the occurrence of new $Cl^-, Br^-$ centers associated with chlorine (bromine) atoms and the compensation of the effect of arsenic on the energy spectrum of electron states.

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Study Of The Total Reaction Cross Section Of 17.0 Mev=N 132 Xe + 238 U Heavy Ion Interactions, J.J. Baluch, E.U. Khan, M.S. Zafar, I.E. Qureshi Jan 1998

Study Of The Total Reaction Cross Section Of 17.0 Mev=N 132 Xe + 238 U Heavy Ion Interactions, J.J. Baluch, E.U. Khan, M.S. Zafar, I.E. Qureshi

Turkish Journal of Physics

We have studied heavy ion nuclear interactions of 17.0 $MeV/N$ $^{132}Xe+^{238}U$ using muscovite mica as Solid State Nuclear Track Detector (SSNTD). Experimental reaction cross section has been determined by two independent methods. Theoretical reaction cross section has been calculated by a classical formula taking into account the energy dependence of the nuclear radius parameter. The cross section determined in the present work has been compared with those at two other energies for the same reaction.

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Resonance Production Of New Resonances At Ep And \Gamma P Colliders, A. Çeli̇kel And M. Kantar Jan 1998

Resonance Production Of New Resonances At Ep And \Gamma P Colliders, A. Çeli̇kel And M. Kantar

Turkish Journal of Physics

We study the resonance production of new particles predicted by preonic models at Linac-Ring type $ep$ and $\gamma p$ colliders. It is shown that these machines will allow to investigate the new particles with masses up to few TeV scale.

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Eects Of Post Deposition Treatments On Vacuum Evaporated Cdte Thin Films And Cds=Cdte Heterojunction Devices, Habibe Bayhan, Çiğdem Erçelebi̇ Jan 1998

Eects Of Post Deposition Treatments On Vacuum Evaporated Cdte Thin Films And Cds=Cdte Heterojunction Devices, Habibe Bayhan, Çiğdem Erçelebi̇

Turkish Journal of Physics

$CdTe, CdS$ thin films and $n-CdS/p-CdTe$ heterostructures have been prepared by conventional vacuum evaporation technique. Some post deposition treatments to optimize the device efficiency have been analyzed and the effects of the individual process steps on the material and device properties were investigated. Annealing in air with and without $CdCl_2$-treatment decreased the $CdTe$ resistivity. The $CdCl_2$-dip followed by annealing in air at $300^{\circ}C$ for 5 min improved the grain size and polycrystalline nature of $CdTe$ thin films. Solar efficiency improvements were achieved when heterojunctions were prepared on successively treated (i.e. etched, air annealed, $CdCl_2$-processed) $CdTe$ surfaces. Etching of the $CdTe$ …

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The Structure Of Liquid Alloys With Chemical Short Range Order, Serap Dalgiç, Seyfettin Dalgiç, Mehmet Tomak Jan 1998

The Structure Of Liquid Alloys With Chemical Short Range Order, Serap Dalgiç, Seyfettin Dalgiç, Mehmet Tomak

Turkish Journal of Physics

We present a study of the structural properties of liquid binary alloys with chemical short range order starting from the effective interatomic pair potentials. The interatomic pair potentials are derived using the second order pseudopotential theory and the static structure is obtained using the modified hypernetted chain approximation. The partial structure factors $S_{ij}(q)$ and the concentration - fluctuation structure factor $S_{cc}(q)$ are calculated to analize the ordering tendencies in a binary alloy. In this work, liquid Li-Mg alloy is studied as a test case. The agreement between theory and experiment is quite good. We conclude that the structural properties of …

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Influence Of Thermal Conductive Material On The Activation Energy Of Amorphous Silicon Thin Films, Sevilay Uğur, Merih Seri̇n Jan 1998

Influence Of Thermal Conductive Material On The Activation Energy Of Amorphous Silicon Thin Films, Sevilay Uğur, Merih Seri̇n

Turkish Journal of Physics

The activation energy of amorphous silicon thin films are usually measured by placing the thin film sample on a heating surface and monitoring the change in the dark conductivity as a function of temperature. The most widely used devices for temperature measurements are surface thermometers and thermocouples. Sensors such as surface thermometers or thermocouples simply measure temperature by reaching an equilibrium state with the measured environment. If the heat conduction to the sensor somehow is obscured by several reasons (sensors having a much larger dimensions than the thin film or not having proper vacuum) different thermal conduction to the sensor …

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Search For Supersymmetry At \Gammap - Colliders, A. U. Yilmazer Jan 1998

Search For Supersymmetry At \Gammap - Colliders, A. U. Yilmazer

Turkish Journal of Physics

We discuss the possibility of searching supersymmetry at TeV scale $\gamma p$ colliders proposed recently. Theoretical predictions are derived within the framework of minimal supersymmetric standard model (MSSM) with R-parity conservation. Productions of squarks, gluinos, charginos and neutralinos through the processes $\gamma p\rightarrow\tilde{q}\tilde{w}X$, $\gamma p\rightarrow\tilde{q}\tilde{g}X$, $\gamma p\rightarrow\tilde{q}\tilde{\gamma}X$ (or $\tilde{q}\tilde{z}$) and $\gamma p\rightarrow\tilde{q}\tilde{q}^*X$ are considered. Cross sections for different initial beam polarizations are calculated and it is shown that polarization asymmetries are sensitive to the particle masses. Discovery mass limits of the superpartners are tabulated for various $\gamma p$ colliders at different center of mass energies. The results are compared with …

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Discovery Limits For New Resonances At Ep And \Gammap Colliders, M. Kantar Jan 1998

Discovery Limits For New Resonances At Ep And \Gammap Colliders, M. Kantar

Turkish Journal of Physics

We study the resonance production of new particles at Linac-Ring type $ep$ and $\gamma p$ colliders.

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Heavy Quark Production At \Gammap Colliders, O. Çakir, M. Yilmaz Jan 1998

Heavy Quark Production At \Gammap Colliders, O. Çakir, M. Yilmaz

Turkish Journal of Physics

Heavy quark pair production at $\gamma p$ colliders is discussed. It is shown that the numbers of $t\bar{t}$ pairs are sufficiently large for investigation of the top quark properties in detail.

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Studies Of Structure Of Ceramic Materials Containing Molibdenum Particles Within The Framework Of Theory Of Non-Homogeneous Systems, Sh. Kami̇lov, M. Karabaeva, U. Abdurahmanov Jan 1998

Studies Of Structure Of Ceramic Materials Containing Molibdenum Particles Within The Framework Of Theory Of Non-Homogeneous Systems, Sh. Kami̇lov, M. Karabaeva, U. Abdurahmanov

Turkish Journal of Physics

The structure of ceramic materials containing molibdenum powder is considered within the framework of leakage theory. Determined are the density of the endless cluster, volumetric parts of the skeleton and dead ends, as well as their dependence on the component concentration. Volumetric part of the skeleton near the threshold of leakage makes a negligible part of the full volume.

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Measurement Of The Compton And Coherent Scattering Differential Cross-Sections, Yakup Kurucu, Salih Erzeneoğlu, Rıdvan Durak, Yusuf Şahi̇n Jan 1998

Measurement Of The Compton And Coherent Scattering Differential Cross-Sections, Yakup Kurucu, Salih Erzeneoğlu, Rıdvan Durak, Yusuf Şahi̇n

Turkish Journal of Physics

The total atomic Compton and coherent scattering differential cross section of Al, Sn and Ta for 59.5 keV gamma rays of Am-241 point source have been measured for scattering angles $\theta=81^{\circ}$, $85.5^{\circ}$, $90^{\circ}$ and $94.5^{\circ}$ by a direct method with an energy dispersive x-ray spectrometer. The background correction and detection efficiency are also included the study. The experimental results are comparatively given with some available theoretical data obtained with some approximation methods.

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The Structure Of (001) Csl Twist Boundaries In Fcc Metals, A. Ghafoor, S.A. Ahmad, B.A.S. Faridi Jan 1998

The Structure Of (001) Csl Twist Boundaries In Fcc Metals, A. Ghafoor, S.A. Ahmad, B.A.S. Faridi

Turkish Journal of Physics

Computer simulation techniques based on discrete lattice approach and empirical many-body potentials have been used to study the structure and energy of $\Sigma = 5$, and $\Sigma = 13$ coincident site lattice (001) twist boundaries in three fcc metals. Energy computed for $\Sigma = 5$ boundary in copper is 17.5 \% less than the earlier result obtained by using pair potential. However the present calculations of twist boundary energies are somewhat higher than the results obtained using embedded atom method.

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The Influence Of Solvents On Formation Of The Molecular Geometry Of [{Fe(Salphen)}_2o], Mehmet Kabak, Ayhan Elmali Jan 1998

The Influence Of Solvents On Formation Of The Molecular Geometry Of [{Fe(Salphen)}_2o], Mehmet Kabak, Ayhan Elmali

Turkish Journal of Physics

The crystal structure and magnetic properties of the complex (I)=[$\{$Fe(salphen)$\}_2$\-O]$\cdot$(C$_4$\-H$_8$SO) and (II)=[$\{$Fe(salphen)$\}_2$O]$\cdot$(C$_4$H$_8$O$_2$)\- (salphen H$_2$=N,N'-o-phenylenebis\-(salicylidene-imine)) were recently reported [1, 2]. This complex crystallized with the solvents of dimethyl sulfoxide and dioxane. In this paper, we investigate the influence of the solvents on the formation of the molecular geometry and study the orbital mechanism of the magnetic super-exchange interactions of this complex.

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The Relation Between Dislocation Density And Crystal Crosscut In \Beta-Sn Grown By Modified Bridgman Method, Bahattin Düzgün, İbrahim Karaman, Nazım Uçar Jan 1998

The Relation Between Dislocation Density And Crystal Crosscut In \Beta-Sn Grown By Modified Bridgman Method, Bahattin Düzgün, İbrahim Karaman, Nazım Uçar

Turkish Journal of Physics

Crystals $\beta$-Sn are grown from ingots of 99.99\% purity by modified Bridgman method under $10^{-3}$ torr pressure and oriented by Laue back reflection method. The relation between crystal crosscut and dislocation density calculated using etch hillock technique is investigated. It is found that the dislocation density increases with increasing crystal crosscut.

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