New High Tc-Value Investigated in Superconducting System YBa2（C u3）1-xA gxO6.5x＋δ

作     者：Emad K. Al-Shakarchi Salwan K.J. Al-Ani Wedad. M. Faysal 

作者机构：Physics Department College of Science Al-Nahrain University Baghdad Iraq Physics Department College of Science Baghdad University Baghdad Iraq 

出 版 物：《Journal of Physical Science and Application》 (物理科学与应用（英文版）)

年 卷 期：2012年第2卷第9期

页      面：352-358页

学科分类：080705[工学-制冷及低温工程] 081704[工学-应用化学] 07[理学] 070205[理学-凝聚态物理] 08[工学] 0817[工学-化学工程与技术] 0807[工学-动力工程及工程热物理] 0703[理学-化学] 070301[理学-无机化学] 0702[理学-物理学] 

主　　题：Superconductor compound 123-compound resistivity measurements X-ray diffraction. 

摘      要：A ceramic superconductor compound with composition YBa2（C u3）1-xA gxO6.5x＋δ has been prepared experimentally by solid state reaction from principal roots of high purity materials like Y203, BaO, CuO and Ag20. The study was concentrated on the effect of partial substitution of Ag with respect to Cu atoms by the ratios （x = 0, 1, 0.2, 0.3, 0.4 and 0.5） through different analysis and measurements. X-ray diffraction （XRD）, Scanning Electron Microscope （SEM） and Resistivity measurement is play an important role to show the improvement on high superconducting phase. It was found that the best substituted value of （x = 0.5） investigated a favor value of Tc equal nearly to （123 K）, due to more excess of Ag atoms in the structure. X-ray diffraction showed an orthorhombic structure related to high-To phase with high stability through diminishing some peaks related to low temperature superconducting phase, that was related to presence of multiphase derivative from YBCO-phase. SEM pictures give us more details on the surface morphology, grain and grain boundaries, it gives an indication on successful of sintering process, the last one is very important in forming superconducting phase.