TRANSPORT-PROPERTIES OF SINGLE-CRYSTAL HGBA2CA2CU3O8+DELTA

We report the first measurements of the transport properties of single crystals of HgBa2Ca2Cu3O8+delta. Data for the in-plane and out-of-plane resistivity, in-plane Hall coefficient and in-plane thermoelectric power of single crystals with onset temperatures as high as 134 K are presented. The in-plane resistivity, Hall coefficient and thermoelectric power all indicate that these crystals are underdoped, which may offer at least a partial explanation for the strong pressure dependence of T-c observed in this compound. The in-plane Hall coefficient shows a strong temperature dependence in accord with other cuprate superconductors. A calculation of the cotangent of the Hall angle (cot theta(H)) reveals that the relation cot theta(H)=AT(2)+B is obeyed to high precision in these crystals, despite strong curvature of the in-plane resistivity. Data are also reported for the influence of magnetic field on the resistive transition, for fields of up to 7 T applied both parallel and perpendicular to the crystallographic c-axis. These latter measurements give an estimate for the anisotropy of H-c2, implying a value which is intermediate between that found for YBa2Cu3O7-delta and Bi2Sr2CaCu2O8+x.