c-axis resistivity of Hg-1201 single crystals

The out-of-plane (c-axis) resistivity, rho(c), of Hg-1201 crystals has been determined. The values obtained, i.e., rho(c)(300 K) similar to 0.3-0.4 Oh m cm, an found to be similar to those of Tl-2201 and Hg-1223, and a quasi-T -independent rho(c) is observed in the normal state. The T-c value of 92 K, obtained from the rho(c)(T) curves, confirms the nearly optimized stale of this crystal. The T dependence of the irreversibility line (IL), obtained from the rho(c)(T)(H) curves (H parallel to c-axis geometry), is found to b e similar to that determined magnetically. The correlation between rho(c) a nd the IL location in the (B,T) plane emphasizes the strong influence of th e separating mercury layers upon the c-axis transport properties of this cu prate, (C) 1998 American Institute of Physics. [S0021-8979(98)05920-9].