Microwave absorption in the mixed state of Bi 2Sr 2CaCu 2O δ+gd single crystals

Abstract

We have measured the microwave absorption at 10 GHz, in Bi 2Sr 2CaCu 2O δ+δ single crystals (T c=88 K) in the mixed state. We show that in our geometry, the absorption reflects the dissipation of the r.f. currents along the ĉ axis. We find a temperature dependent characteristic field H ∗, beyond which the normal state dissipation is recovered: this field may be identified with the decoupling field B D estimated by Daemen et al.