Effect of distribution of powder size on estimation of critical current densities in polycrystalline Sr0.6K0.4Fe2As2 superconductors

► We prepared polycrystalline (SrK)Fe2As2 by one step solid state reaction method. ► According to addition of Ag, powder size increases. ► The apparent Jc is increased by increasing distribution of powder size. ► The local Jc is calculated with distribution of powder size. ► The local Jc is order of 1010 A/m2.