تحضير ودراسة المركبات SnxBa4Ca2Cux+4Oy وYnBa5Cun+5Oy == Preparation and Characterization of the SnxBa4Ca2Cux+4Oy and YnBa5Cun+5Oy Compounds
Author name:
رؤى فخري هادي
Supervisor name:
عماد خضير الشكرجي
General topic:
Physics
Specific topic:
Physics
Degree:
Master
University:
Al-Nahrain University - College Of Science - Physics Department
Language:
English
University location:
Baghdad
First pages:
26T1718 - p.pdf
Abstract:
The present study includes the preparation of SnxBa4Ca2Cux+4Oy and YnBa5Cun+5Oy compounds with (x = 3, 4, 5, 6, 7) and (n=3, 5, 7) by solid state reaction (SSR) method. The study was to conclude the superconductor behavior of both compounds. The prepared samples were analyzed by Meissner effect primary, and the excess oxygen content was measured by using Iodomertric titration method. The samples characterized by XRD patterns with computer program that was used to determine the value of lattice constant, Scanning Electron Microscope (SEM), Energy dispersive X - ray spectroscopy (EDS) to study the grain morphology and also resistivity measurement was performed by Van der Pauw method to conclude the nature of behavior.The resistivity measurement results of Sn - Ba - Ca - Cu - O system showed that the semiconducting behavior, increases with decreasing the temperature toward low temperature, the lowest and the highest normal resistivity were found at x=6 and at x=4, respectively. The system Y - Ba - Cu - O showed a superconductor behavior with high transition temperature, the Tc at n=3 of about (113.6 K), the sample prepared with n=5 has Tc=113 K, meanwhile the sample prepared with n=7 has Tc=105 K.The x - ray analyses for SnxBa4Ca2Cux+4Oy samples showed that the tetragonal structure, and the c - parameter increased by increasing the value of (x) until reach to maximum value at x=5 then return back decreasing at x=6 and 7. The x - ray diffraction analysis of the compound YnBa5Cun+5Oy has orthorhombic phase and when Y - atom concentration and the number of CuO2 layer increased tend to increase b and c - axis.The Scanning Electron Microscopy (SEM) results showed that the appearance of nanostructure in Sn6Ba4Ca2Cu10O22 and Sn7Ba4Ca2Cu11O24 samples in the range (100 - 300 nm), whereas the other samples of Sn - familywas a microstructure. On the other hand, the Y - 358 had large grains randomly comparable with Y - 5 5 10, Y - 7 5 12 addition to absent the interfaces distances from Y - 358. The results of EDS showed that the agreement of the peaks appeared with the theoretical values.
