Superconducting and Normal State Parameters of Bi2.2Sr2Ca0.8Cu2O8+δ Single Crystals:A Comparison with Ba2YCu3O7

Magnetic and magnetotransport properties were studied on Bi2.2Sr2Ca0.8Cu2O8+δ single crystals. The normal state resistivity in the a-b plane varies linearly with temperature and extrapolates to zero at T=0. The slopes of the upper critical field are -4.5±1 (-0.55) T/K for H perpendicular (parallel) to the c-axis. The coherence length is calculated to be ~30Å in the a-b plane but only ~4Å perpendicular to it. ξc is thus shorter than the 12Å spacing between the Cu-O double layers. From Hc1 and Hc2 data, the Sommerfeld parameter γ is deduced