Measurement of transition temperatures (simultaneously at DC and microwave frequencies) on high†T<inf>c</inf> superconducting systems

A technique for the simultaneous measurement of the dc conductivity and microwave (ac) properties on the same sample is described. The difference in transition temperatures between dc and microwave frequencies (i) at ≈6.2 GHz (J‐band), ≈9.2 GHz (X‐band), ≈13.5 GHz (P‐band), and ≈17.8 GHz (P‐band) on YBaCu oxide and (ii) at ≈6.2 GHz on YBaCu oxide thin films and BiPbSrCaCu oxide has been evaluated. From the observations of these simultaneous measurements, the energy dependent variations of these simultaneous measurements, the energy dependent variation of ΔTc (Tc(dc) – Tc(ac)) and the non‐zero microwave power loss beyond the superconducting transition temperature are discussed. Copyright © 1994 WILEY‐VCH Verlag GmbH & Co. KGaA