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- Thermoluminescence (2)
- A-Si:H (1)
- A-Si:H p-i-n solar cells. (1)
- A. Dark conductivity; B. Photoconductivity; Rf power density; D. Activation energy; E.Hydrogenated amorphous silicon. (1)
- A. High temperature superconductors; B. Hot pressing; C. YBCO; D. I-V; E. AC susceptibility. (1)
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- A. Hydrogenated amorphous silicon nitride; B. Substrate temperature; C. Dark conductivity; D. Photoconductivity; E. Optical gap. (1)
- Acetylene (1)
- Amorphous (a-) Si:H p-i-n solar cells (1)
- Angular Correlation (1)
- Back reflectors (1)
- Boundary Element Method (1)
- CPM (1)
- Charge-exchange (1)
- Chemical synthesis (1)
- Composite materials (1)
- Coriolis force. (1)
- Coronal mass ejections (1)
- Coulomb system (1)
- Critical current density (1)
- Cross section. (1)
- Decay width (1)
- Defect structure (1)
- Deformation parameter (1)
- Dielectric constant (1)
- Dielectrics (1)
- Dispersion analysis (1)
- Distribution of annealing activation energies. (1)
- Effects of nonstoichiometry (1)
- Electromagnetic transitions. (1)
- Electron Scattering. (1)
Articles 31 - 60 of 65
Full-Text Articles in Physical Sciences and Mathematics
Formation Energy In Al-Mg Alloy By Positron Annihilation Lifetime Technique (Palt), Mamduh Abedl-Rahman, Emad A. Badawi, Essmat Mahmoud Hassan, Gamal Yahya
Formation Energy In Al-Mg Alloy By Positron Annihilation Lifetime Technique (Palt), Mamduh Abedl-Rahman, Emad A. Badawi, Essmat Mahmoud Hassan, Gamal Yahya
Turkish Journal of Physics
The propose of the present work is to study the interaction of positrons with quenched-in defects and clustered atoms to estimate formation enthalpy in series 50xx of commercial Al-Mg alloys, namely, 5049, 5051,5052 and 5083 at various concentrations: 1.9, 2.09, 2.46 and 4.44 wt % of Mg, respectively. Typically additional impurities were mainly Si, Fe, Cu, Cr and Ti. The monvacancy formation energy of Al-Mg alloys was measured from a trapping model analysis of the T-dependence of the positron lifetime.
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.
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.
Experimental Investigation Of Temperature Effect On Refractive Index Of Dye Laser Liquids, Şeref Yaltkaya, Ramazan Aydin
Experimental Investigation Of Temperature Effect On Refractive Index Of Dye Laser Liquids, Şeref Yaltkaya, Ramazan Aydin
Turkish Journal of Physics
In this work, refractive index of selected dye laser solutions were measured by fiber optic sensor. The fiber optic probe was dipped into the liquids and according to Fresnel's Reflection Law, refractive index values were obtained at the wavelength of the laser utilized. The solutions consisted of Rhodamine 6G, Rhodamine B and Coumarin 481 dissolved in methanol, and ethylene glycol, respectively. Refractive index variations of the dye solutions and their solvents with temperature were measured and the refractive index temperature coefficient dn/dT were calculated at the wavelength of 780 nm.
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.
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 …
Stimulated Polarization In \Bf Linbo_{3} And \Bf Ba_{2}Nanb_{5}O_{15} Crystals, Süleyman Çabuk, Amirullah Mamedov
Stimulated Polarization In \Bf Linbo_{3} And \Bf Ba_{2}Nanb_{5}O_{15} Crystals, Süleyman Çabuk, Amirullah Mamedov
Turkish Journal of Physics
Thermally Stimulated Conductivity (TSC) and thermoelectret state in LiNbO_{3} and Ba_{2}NaNb_{5}O_{15} were measured as a function of temperature and time in dark and under UV excitation at liquid nitrogen temperature. Effect of polarization and the other external influences on thermoelectret were investigated. The thermal activation energy levels of traps were determined from TSC measurements as well as parameters (electric field, temperature, etc.) which are necessary for characterizing thermoelectrets were obtained.
Effect Of Rf Power On The Electrical Properties Of Glow-Discharge A-Si:H, Hüseyi̇n Tolunay
Effect Of Rf Power On The Electrical Properties Of Glow-Discharge A-Si:H, Hüseyi̇n Tolunay
Turkish Journal of Physics
Hydrogenated amorphous silicon films were prepared in an rf glow-discharge system by decomposing undiluted silane at various rf power densities. Dark conductivity and photoconductivity of the films have been measured in the temperature range 420K-100K at four different photon fluxes. It was observed that both dark conductivity and photoconductivity increase with increasing rf power density.
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 …
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.
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 …
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 …
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 …
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.
Properties Of Cold And Hot Polarized Nuclear Matter With Realistic Nucleon Nucleon Interaction, S. A. Moharram
Properties Of Cold And Hot Polarized Nuclear Matter With Realistic Nucleon Nucleon Interaction, S. A. Moharram
Turkish Journal of Physics
The Thomas-Fermi (TF) model is used to calculate the equation of state ofthermal polarized nuclear-matter (NM) within a nonrelativistic Hartree-Fock (HF) scheme. The potential employed is a new realistic version of the density-dependent M3Y effective nucleon-nucleon (NN) interaction where the Yukawa strengths are based on the G-matrix of the Paris interaction. To study the basic properties of asymmetric nuclear matter, this potential is generalized by introducing spin and spin-isospin components into the original M3Y effective NN interaction. The resulting equation of state (EOS) is soft. The results obtained are in reasonable agreement with previous theoretical estimates.
Collapse Of Interstellar Molecular Clouds, E. Rennan Pekünlü, Esra Tiğrak, Di̇cle Zengi̇n
Collapse Of Interstellar Molecular Clouds, E. Rennan Pekünlü, Esra Tiğrak, Di̇cle Zengi̇n
Turkish Journal of Physics
In this paper we systematically investigate the length and time scales of an interstellar molecular cloud for collapse under the influence of self--gravity, magnetic field and Coriolis forces. We used Magnetohydrodynamic (MHD) equations in linearized form in order to explore the dynamical evolution of perturbations. We found that both the Lorentz force and the Coriolis force support the cloud against self contraction, i.e., they introduce stabilizing effect against gravitational instability. Of the two cloud types with the same physical size, only those threaded by an interstellar magnetic field without rotation or those rotating without magnetic field will survive against gravitational …
Investigation Of The Critical Current Density Of Ybacuo High-Temperature Superconductor Ceramic, Ioseb R. Metskhvarishvili, Nodar P. Kekelidze, Magda R. Metskhvarishvili
Investigation Of The Critical Current Density Of Ybacuo High-Temperature Superconductor Ceramic, Ioseb R. Metskhvarishvili, Nodar P. Kekelidze, Magda R. Metskhvarishvili
Turkish Journal of Physics
The method of high harmonics is used to investigate penetration of low magnetic fields within the Y_{1}Ba_{2}Cu_{3}O_{7} high-temperature superconductor ceramic. Given experimental results are explained by the modal dependencies between the value of critical current density and the magnetic induction B: j_{c}(B) = j_{c}(0){\frac{{B_{0}^{2}}} {{B_{0}^{2} + B^{2}}}}.
Justification Of Spherical Approximations Using Degree Of Linear Polarization Of Hot Electron Luminescence From Gaas Crystal, Mohammad Naeem Khalid, Shazia Yasin
Justification Of Spherical Approximations Using Degree Of Linear Polarization Of Hot Electron Luminescence From Gaas Crystal, Mohammad Naeem Khalid, Shazia Yasin
Turkish Journal of Physics
The anisotropic momentum distribution of photoexcited hot electrons on recombination with holes at the acceptor level produces linearly polarized luminescence. It is found that the degree of linear polarization (DoLP) of the luminescence over the whole width of the first heavy hole peak (0HH) is not constant. Calculations within the spherical approximation show that in bulk GaAs the DoLP over the 0HH peak should vary from zero, at the low energy side, to its maximum value (0.33), at the high energy side of the 0HH peak, for the electric vector of excitation \hat {\boldsymbol e}\vert \vert [110] excitation geometry and …
The Spectral Properties Of Two Interacting Electrons In A Quantum Dot, Mohammad Elsaid
The Spectral Properties Of Two Interacting Electrons In A Quantum Dot, Mohammad Elsaid
Turkish Journal of Physics
The shifted 1/N expansion method is used to study the spectral properties of two interacting electrons confined in a QD, under influence of a uniform magnetic field of arbitrary strength. We give explanation to the transitions in the spin and angular momenta of the QD ground state as the magnetic field sweeps. The electron addition energy is also calculated. Based on different comparisons , the shifted 1/N expansion method gives very good result against various methods used to study the spectra of a two electron QD.
Dispersion Analysis Of Sns And Snse, Haluk Şafak, Mustafa Merdan, Ö. Faruk Yüksel
Dispersion Analysis Of Sns And Snse, Haluk Şafak, Mustafa Merdan, Ö. Faruk Yüksel
Turkish Journal of Physics
The reflectance spectra of single crystals of SnS and SnSe were measured at normal incidence by unpolarized light. The refractive indices of speciemens were calculated by Kramers-Kronig Analysis. On the basis of the Wemple diDomenico single oscillator model, the dispersion parameters were determined. It is found that the parameters obtained by unpolarized light are, in general close to those reported for polarized cases. Morever, a close similarity were observed with E//b polarization for SnS.
Modulation Frequency-Dependence Of Photocurrent In Amorphous Si:H P-I-N And Chalcogenides, Bengü Kaplan, Ruhi̇ Kaplan
Modulation Frequency-Dependence Of Photocurrent In Amorphous Si:H P-I-N And Chalcogenides, Bengü Kaplan, Ruhi̇ Kaplan
Turkish Journal of Physics
The effects of modulation frequencies (up to 35 kHz) on the intensity- and temperature-dependence of photocurrent of amorphous (a-) Si:H p-i-n and chalcogenide glasses (a-Se and a-As_2Se_3) were investigated in detail. The variation of exponent \nu, and in the power-law relationship \sigma_{ph} or I_{ph} \propto G^{\nu} between the photoconductivity (or photocurrent) and the generation flux, with modulation frequency in chalcogenide glasses is found to be much stronger than that of a-Si:H p-i-n. The activation energies, calculated from the temperature-dependent photocurrent, were determined at different modulation frequencies. We conclude that the activation energy increases with incresing modulation frequencies at low excitation …
Free-Carrier Absorption In Quantum Well Structures For Alloy-Disorder Scattering, Guseyn Behbudoglu Ibragimov
Free-Carrier Absorption In Quantum Well Structures For Alloy-Disorder Scattering, Guseyn Behbudoglu Ibragimov
Turkish Journal of Physics
A free-carrier absorption theory is given for quantum wells structures in III-V semiconducting materials, for the case when the carriers a scattered by alloy-disorder. It is found that absorption coefficients due to alloy-disorder and to phonons are of the same order. Results are shown that the absorption coefficient decreases with increasing photon frequency and increases with increasing temperature. It is also shown that the absorption coefficient increases with decreasing layer thickness. We also found that absorption in quantum wells structures is enhanced by going to quantum wells of smaller thickness over its value in the bulk III-V semiconducting materials.
Spatial Non-Uniformity Measurements Of Large Area Silicon Photodiodes, Murat Durak, Farhad Samadov, A. Kamuran Türkoğlu
Spatial Non-Uniformity Measurements Of Large Area Silicon Photodiodes, Murat Durak, Farhad Samadov, A. Kamuran Türkoğlu
Turkish Journal of Physics
Accurate determination of the responsivity of silicon photodiodes are highly desired in photometry. The change of responsivity over the surface, the so-called spatial non-uniformity, effects power measurements especially in photodiodes with large active areas. To study this effect, first an intensity-stabilized laser source-optics has been established. A purpose-built step-motor controlled two axis micro mechanical stage has been designed to scan the photodiode surface. In this study, the technique and the results of the uniformity mapping of large area research-grade silicon photodiodes which were measured on the purpose-built set-up are presented.
Study Of The Effectiveness Of Various Solar Wind Parameters In The Development Of Geomagnetic Storms During Interplanetary Events, -- Badruddin
Turkish Journal of Physics
We have selected some interplanetary events responsible for geomagnetic disturbances of varying magnitude, fairly different from one another. We then tried to find the heliospheric structure (e.g. shock/sheath and/or CME/magnetic cloud) responsible for individual disturbances. We have discussed and inter-compared these structures in their plasma and field parameters as well as in their geomagnetic effects. As a parameter for geomagnetic disturbance we have chosen index Dst, to compare it with variations in field and plasma to heliospheric response structures. We considered parameters such as total field strength, its north-south component, solar wind density, temperature and velocity. In addition, we have …
A New Metallicity Calibration For Dwarf Stars With Rgu-Photometry, Sali̇h Karaali̇, Selçuk Bi̇li̇r
A New Metallicity Calibration For Dwarf Stars With Rgu-Photometry, Sali̇h Karaali̇, Selçuk Bi̇li̇r
Turkish Journal of Physics
We have adopted the procedure of Carney to obtain a metallicity calibration for dwarfs utilising RGU-photometry. For this purpose we selected 76 dwarfs of different metallicities from Carney and from Strobel et al., and evaluated their \delta (U-G) ultra-violet excess relative to the Hyades by transforming UBV magnitudes to RGU via the metallicity dependent equations of Ak-Güngör. The \delta_{0.6}/\delta M normalized factors of Sandage transform \delta (U-G) excess at any G-R to \delta \equiv \delta_{1.08}, i.e. the ultra-violet excess at G-R = 1.08 mag, corresponding to B-V = 0.60 mag in the UBV-system. Finally, the (\delta, [Fe/H]) pairs were shown …
Microstructure And Critical Current Of Hot-Pressed Ybco Ceramics, Şadan Özcan, Tezer Firat, Engi̇n Özdaş
Microstructure And Critical Current Of Hot-Pressed Ybco Ceramics, Şadan Özcan, Tezer Firat, Engi̇n Özdaş
Turkish Journal of Physics
The effect of hot-pressing (HPing) on the densification and the superconducting properties of YBCO were investigated. The phases and microstructure were analysed by XRD and SEM and transport properties were studied by I-V and AC susceptibility measurements. Relative density up to 93% and critical current density of 509 A/cm^{2} at 77 K were achieved through uniaxial HPing at 800°C under 325 kg/cm^{2} pressure for 4 hours. HPing raised the J_{c} from 80 A/cm^{2} to 509 A/cm^{2}. These results and AC susceptibility measurements reveal that the weak links or pinning forces were improved by increasing HPing pressure.