T. Mamiya et al., ELECTRICAL-RESISTIVITY OF NONSUPERCONDUCTING LA4BACU5O13 AND LA5SRCU6O15-BASED COMPOUNDS DOWN TO THE MK TEMPERATURE-RANGE, Physica. B, Condensed matter, 194, 1994, pp. 1523-1524
We have measured the electrical resistivity of La4BaCu5O13 and La5SrCu
6O15-based compounds down to 39mK and 16mK, respectively, without obse
rving superconductivity. When the resistivity rho - rho0 was proportio
nal to T(gamma), the exponent gamma ranged from 1.18 to 1.83 for these
compounds. where rho0 is residual resistivity and T is temperature. I
t was ascertained from our measurements down to the mK range that thes
e compounds were not superconducting because of a three-dimensional ne
twork of CuO5 units.