Effect of density on the electrical properties of MgB₂ superconductor

The pellets of commercially available MgB₂ powder were prepared at three different compaction pressure values. The change in compaction pressure changed the bulk density of the sample. Superconducting properties were not affected much with change in preparation condition even though samples show difference in density, porosity and grain size. The normal state electrical properties are found to be dependent on preparation conditions. There is a correlation between room temperature resistivity and residual resistivity ratio (RRR) and resistivity exponent, n values.