Microwave surface impedance measurements on high-T-c superconductors
Jaekel, C × François, I Kyas, G Huning, F Roskos, HG Borghs, Gustaaf Kurz, H #
Czechoslovak jnl of physics
Czechoslovak journal of physics vol:46 pages:1117-1118
We present measurements of the surface impedance of YBa2Cu3O7-delta and Bi2Sr2CaCu2O8+y thin films in the TIIz regime. Below T-c, peaks in the real part of the conductivity are observed in both materials, but differ in the temperature dependence. Investigations of Pr-doped YBCO reveal deviations from the T-linear behavior of the resistivity at characteristic temperatures that shift with the doping level and can be identified with the occurrence of a spin gap. The spin-gap temperature and T-c as a function of doping span a Nagaosa-Lee-type phase diagram in the underdoped regime.