CU-63 NMR PROBE OF SUPERCONDUCTING PROPERTIES IN HGBA2CA2CU3O8- A POSSIBLE REASON FOR T-C=133K(DELTA )

Superconducting properties in HgBa2Ca2Cu3O8+delta, with a transition t emperature of T-c=133 K, have been investigated by measurements of the nuclear spin-lattice relaxation rate, (63)(1/T-1). It has been found that the T1T=const behavior, observed well below T-c, arises from comb ined relaxation channels to vortex cores, as well as from a residual d ensity of states (DOS), N-res, at the Fermi level associated with the gapless superconductivity. From the value of T1T=const in the latter c hannel, the DOS fraction normalized by its value at T-c, N-res/N-Tc, h as been deduced to be as small as similar to 0.05. Based on the two-di mensional gapless d-wave model, the T-c reduction rate, Delta T-c/T-c0 , is estimated to be as small as 0.02 for N-res/N-0 similar to 0.05. I t is pointed out that these measures of the quality of HaBa(2)Ca(2)Cu( 3)O(8+delta) explain why T-c reaches such a high value.