Pseudo-gap phenomenon in the SN-doped mercury-based cuprate superconductors

The Sn-doped mercury-based copper oxide high temperature superconductors, with nominal composition (Hg_1-xSn_x)Ba₂Ca₂Cu₃O _8+δ, have been successfully fabricated. These samples were used to study the pseudo-gap phenomenon in their normal phase. By means of 1n[l/ρ(T) -1/ρ_N(T)] versus 1/7 plots we found three characteristic temperatures T*, T_S, and T_F, which describe the role of pseudo-gap phenomenon. From the stated plots, we are able to estimate the magnitude of the pseudo-gap for our samples. The pseudo-gap Δ_PG changes into the spin pairing dipolar superconducting gap ASPDS, when the Fermi kinetic energy shrinks to zero at the critical temperature T_c. It is proved that the spin pairing dipolar superconducting gap Δ_SPDS = √(2/3)Δ_T, where, Δ_T being the total superconducting gap of the cuprate superconductors, which has the value determined by 2Δ_T = 3.52√3k_BT_c. It is also proved that the spin pairing dipolar superconducting gap is smaller than the dipolar pseudo-gap, Δ_PG.