An investigation of the effect of grain size on some properties of intrinsic Josephson junction

► Grain size, t, determined by SEM, has a key role for intrinsic Josephson Junctions. ► Supercurrent density and Josephson penetration depth are changed with variation of t. ► HgBa2Ca2Cu3O8+x (Hg-1223) consists of intrinsic Josephson junction array. ► The effect of t on electrodynamics parameters of Hg-1223 was investigated by SEM.