SUPERCONDUCTIVITY, STRUCTURE AND RESISTIVITY IN HGBA2CA2CU3O8+DELTA

Samples of HgBa2Ca2Cu3O8+delta were successfully prepared and investig ated. By examining the X-ray diffraction, transmission electron micros copy, magnetization and resistivity, we found that HgBa2Ca2Cu3O8+delta possesses an orthorhombic structure with lattice parameters a = 5.451 (2) angstrom, b = 5.432(2) angstrom and c = 15.826(7) angstrom and a s harp superconducting transition (magnetically determined) at approxima tely 112 K as-synthesized and as high as approximately 135 K after oxy genation. The resistivity vanishes below 134 K, the highest reported f or any superconductor to date. No superstructures of the types previou sly reported in the > 130 K samples were detected in this study. A lin ear T-dependent resistivity which is interpolated to zero at 0 K was a lso observed above approximately 240 K. Below approximately 240 K, dev iation from such a linearity appears, which may be attributable to the fluctuation or spin-scattering effect, assuming that the behavior is intrinsic to HgBa2Ca2Cu3O8+delta.