Non-resonant microwave absorption evidence for intrinsic Josephson coupling in Tl2Ba2CaCu2O8 single crystals

We report the results of our non-resonant microwave absorption (NRMA) studi es on single crystals of Tl2Ba2CaCu2O8 (Tl 2212) which reflect the occurren ce of intrinsic Josephson coupling in these crystals. We have studied the m agnetic field induced microwave absorption at various temperatures from 4.2 K to T-c (similar to 104K) using a standard CW EPR spectrometer (H-dc paral lel to c). We observe the appearance of a characteristic feature in the NRM A signals similar to the ones observed earlier by us in Bi2Sr2CaCu2O8 (Bi 2 212) starting a few degrees below T-c, which on cooling passes through a ma ximum in intensity before disappearing at a further low temperature. This b ehaviour is attributed to the appearance, strengthening and disappearance o f Josephson response consequent to the temperature dependence of the viscos ity of the Josephson medium between the CuO2 superconducting sheets.