Influence of Ag/Cu Substitution on Structural Effect of New High Temperature Superconductor Y3Ba5Cu8O18

Abstract

The class of superconductors ceramic materials has been made from copper oxides mixed with rare earth elements such as yttrium. The new Y-based high temperature superconductor Y3Ba5Cu8O18-δ (Y358), Gholipour et al. (2012), Tavana et al. (2010), Khosroabadi et al.(2014), with Ag/Cu substitution was synthesized through the sol-gel technique by making nano oxide Y, Ba, Cu and Ag. The influence of the doping of Ag atoms into the compound Y3Ba5Cu8O18 was studied by employing XRD pattern, SEM and the electrical resistivity measurements. The room temperature electrical measurements have shown that ceramic Y358 has metal behavior in the normal state. The compound of YBCO family was discovered containing the CuO2 planes and the Cu-O chains. It seems that increasing the number of the CuO2 planes and the position of the Cu-O chains have positive effects on the value of the transition temperature in the Y-based compounds. The analysis of the X-ray diffraction pattern was approved by MAUD software which the Ag ions substitute in symmetrical phase of the sample. The substitution of the Ag ions in the CuO2 plane of symmetric phase has been compared with the Ag ions in the Y123 superconductor, which substitute in the Cu-O chain. The electrical resistivity of these superconductors was measured by 4prob method. The electrical resistivity graph approved the start of transition temperature above 100K.