SUPERCONDUCTING PROPERTIES OF Y2Ba5Cu8Oδ (Y258) POROUS AND NON- POROUS STRUCTURE

Abstract

Solid state reaction method was applied to produce porous and non-porous ceramic materials through a series of heating and grinding. This study revealed the distinguish properties of Y258 in terms of their porous and non-porous structure. The bulk material usually loses its high temperature features due to increase in critical current density. Therefore, it is essential to investigate the porous structure that influences the superconducting properties. The electrical properties of superconductor due to critical temperature, T c and critical current density, J c were determined using Resistivity Measurement System (RMS). The morphological structure of superconductor material was analysed by using Scanning Electron Microscopy (SEM). The grain boundary of porous structure is significant to induce higher conductivity without detriment the critical temperature of the superconductor. The higher J c recorded for porous Y258 was 1.59 A/cm 2 at 50 K. The J c value was higher compared to nonporous optimal structure which is 1.42 A/cm 2. The T c zero for porous and non-porous sample gives the same value which is 78 K for both samples. Results of Y247 doped with Ca were determined for comparison.