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.