Abstract
In the present work influence of the varying grain size on inter and intra granular properties of La1.85Sr0.15CuO4 superconductor are studied. The samples of varying grain size are synthesized via sol gel route by varying sintering temperature. Phase purity of all the samples is confirmed by X-ray diffraction pattern while the varying particle size is checked from Scanning Electron Microscopy (SEM) images. Resistivity and magnetization measurements are carried out to study the magneto-transport properties of the samples. Inter and intra granular contribution to the resistivity and diamagnetic shielding of the sample is clearly visible from the two step behavior in the resistivity and the real part of ac susceptibility measurement respectively. To study quantitatively the impact of varying grain size over inter and intra contributions we calculate critical current density using Bean's critical state model for both inside the grain and for the whole sample assuming that in critical state supercurrents flow throughout the sample as a whole and within the individual grains as well. Both qualitative and quantitative magneto-transport measurements suggest that as the particle size is varied inter granular parameters in general gets more affected than the corresponding intra granular ones.