Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Influence of High Content of Sodium Doping in Bi(pb)2212 Superconductors(Pleiades Publishing, 2023) Faiza, Bouaïcha; Özyüzer, Lütfi; Mosbah, Mohamed-Fayçal; Özyüzer, Lütfi; 04.05. Department of Pyhsics; 04. Faculty of Science; 01. Izmir Institute of TechnologyAbstract: We study here, the effect of high content of sodium doping on structural and electrical properties of Bi(Pb)2212 superconductors. The X-ray analysis results showed that all the prepared samples mainly belong to the superconducting tetragonal phase Bi–(Pb)2212. SEM micrographs show that the grains are closely related and have a characteristic flat shape for the superconductor Bi (Pb) 2212. For the undoped sample, the grains are randomly distributed with an average size of 5 μm. For doped samples, the morphology changes with sodium concentration. Resistivity measurements show that all samples have a superconducting character. © 2023, Pleiades Publishing, Ltd.Article Product Design in Monopolistic Competition(Wiley, 2022) Dindaroğlu, Burak; 01.01. Units Affiliated to the Rectorate; 01. Izmir Institute of TechnologyWe consider a model of monopolistic competition where producers can manipulate an elasticity parameter at an early stage. We interpret this as a choice of product specialization. Lower marginal costs of production lead to more generic products in all equilibria, which lead to fewer varieties under free-entry. Entry of a new firm increases overall specialization and increases prices, that is, the environment exhibits price-increasing competition. The loss of consumer surplus due to higher prices and lower consumption is compensated by the value of additional variety, hence entry also increases consumer surplus. Therefore, price-increasing competition need not be anticompetitive under endogenous specialization.Article Citation - WoS: 2Citation - Scopus: 2Effect of Al Substitution on Structural and Electrical Properties of Bi1.6pb0.4sr2cacu2-X Mx O8+? Superconducting Ceramics(Springer Verlag, 2013) Bouaicha, F.; Özyüzer, Lütfi; Hamel, M.; Benmaamar, F.; Amira, A.; Guerfi, T.; Haouam, A.; Özyüzer, Lütfi; 04.05. Department of Pyhsics; 04. Faculty of Science; 01. Izmir Institute of TechnologyIn this work we study the effect on structural and electrical properties of superconducting compound Bi1.6Pb0.4Sr 2CaCu2-y My O8+δ were M=Al (with y=0-0.6). The samples were prepared by the solid-state reaction method. The samples have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), direct current (DC) resistivity versus temperature ρ(T) and alternative current (AC) susceptibility measurements. Structural analysis shows that the crystalline lattice structure of the prepared sample belongs, mainly, to the superconductive tetragonal phase Bi(Pb)2212. The SEM micrographs show that in the undoped sample the grain size has a random distribution with few grains greater than 5 μm. The grains are very dense and well connected. A quite different microstructure is obtained for the doped samples of which grains are more connected with a flat characteristic shape of Bi(Pb)2212 superconductors. All samples exhibit a superconducting character and Tc and the superconducting volume fraction decrease with increasing rate of aluminum.