The investigation of TB and ZN doped YBCO-123 and YBCO-358 superconductors produced by sol-gel route

In this study, copper-based Y1-x(Tb)xBa2Cu3O7-δ, YBa2Cu3-x(Zn)xO7-δ, Y3-x(Tb)xBa5Cu8O18-δ and Y3Ba5Cu8-x(Zn)xO18-δ superconductor samples prepared using the sol-gel production method were examined. The samples prepared using acetate-based compounds were converted into superconducting bulk form by pressing after three times calcination at 800°C, sintering at 930°C for 24 hours and waiting at 500°C for 5 hours in an oxygen environment. X-ray diffraction (XRD) diffractometry, scanning electron microscopy (SEM) and energy distribution spectroscopy (EDS) are used to characterize the structural properties of the produced samples, temperature-dependent resistivity (ρ-T) measurements are used to determine the electrical properties, and direct current magnetization (VSM) is used to determine the magnetic properties. In addition, Vickers microhardness measurements were used to determine the micromechanical properties. According to the results of XRD analysis of the samples, it was understood that they were in orthorhombic crystal structure, and it was determined that they showed superconducting properties according to the electrical measurement results. In all samples produced in both YBCO phases and both additive types, the doping reduced the critical temperature value for transition to superconductivity. In addition, according to the VSM measurement results, the critical current density values have generally decreased depending on the amount of doping. Also, when the results of Vickers microhardness measurements were examined, it was understood that all Tb and Zn doped samples showed indentation size effect (ISE) behavior and the indentation-induced cracking (IIC) model was the most appropriate model for evaluating the results. It is aimed to examine the effects of the production method of the bulk samples produced in two different YBCO phases, the type and ratio of dopants with partial substituon on the structural, electrical, magnetic and mechanical properties of the material, and as a result to contribute to the production of materials with improved superconductivity and high technological performance.