YMF18 özet kitapçığı - Department of Physics

18. Yoğun Madde Fiziği – Ankara Toplantısı, Orta Doğu Teknik Üniversitesi, 25 Kasım 2011Role of annealing time and temperature on structural and superconductingproperties of (Bi,Pb)-2223 thin films produced by sputteringG. Yildirim * , A. Varilci, M. Akdogan, S. Bal, G. Ozdemir, C. Terzioglu, M. Dogruer**,and E. Yucel*Abant Izzet Baysal University, Department of Physics, Bolu–Turkey 14280**Mustafa KemalUniversity, Department of Physics, Hatay–Turkey 31034P13This study reports the effect of annealing time (15 m, 1.5 h, and 3 h) and temperature (850,860, and 870 °C) on the structural and superconducting properties of thin films by means ofscanning electron microscopy (SEM), X-ray analysis (XRD), electron dispersive X-ray(EDX), resistivity and transport critical current density (J c ) measurements. Zero resistivitytransition temperatures (T c ) of the films produced are estimated from the dc resistivitymeasurements. In addition, the phase and lattice parameters are determined from XRDpatterns when the microstructure, surface morphology and element composition analyses ofthe samples are investigated by SEM and EDX measurements, respectively. The resultsindicate that T c values of the films obtained are observed to be in a range of 23–102 K. The T cof the film annealed at 870 °C for 3 h is found to be the smallest (23 K) while the filmannealed at 860 °C for 3 h is noted to obtain the maximum T c value (102 K). On the otherhand, the maximum (minimum) J c is found to be about 2068 A/cm 2 (20 A/cm 2 ) for the filmannealed at 860 °C for 3 h (870 for 3 h). Moreover, according to the refinement of cellparameters done by considering the structural modulation, the greatest Bi-2223 phase fractionis noticed to belong to the film annealed at 860 °C for 3 h. Furthermore, SEM measurementsshow that the best surface morphology, largest grain size and grain connectivity are observedfor that film. Based on these results, T c and J c values of the samples studied are found todepend strongly on the microstructure. As for EDX results, the elements used for thepreparation of samples are observed to distribute homogeneously. The aim of this study is notonly to investigate the changes of structural and superconducting properties of the filmsproduced in the varied time and temperature but also to determine the best ambient for thefilm fabrication and show the feasibility of obtaining Bi-2223 film with tailored structure.45