The relationship between the pseudo-gap and the spin pairing dipolar superconducting gap in the Sn-doped Hg-1223 high temperature superconductors

The Sn-doped mercury-based high temperature superconductors, (Hg1-xSnx)Ba2Ca2Cu3O8+delta, were used to study the pseudogap phenomenon. By means of ln[1/rho (T) - 1/rho (N)(T)] vs. 1/T plots we found three characteristics 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 pseudogap, Delta (PG), for OUT samples. During lowering temperature from T-F to T-C, the pseudo-gap Delta (PG) changes smoothly into the spin pairing dipolar superconducting gap Delta (SPDS), when the Fermi kinetic energy shrinks to zero at the critical temperature T-C. The spin pairing dipolar superconducting gap can be related to the total superconducting gap Delta (T), i.e. Delta (SPDS) = root2/3 Delta (T). Hence the cuprate's superconducting gap is given by 2 Delta (T) = 3.52 root 3k(B)T(C). The spin pairing dipolar superconducting gap is experimentally shown to be smaller than the dipolar pseudo-gap, Delta (PG). (C) 2001 Elsevier Science Ltd. All rights reserved.