Anomalous magnetic behaviour in non-resonant microwave absorption study ofBi-2212 superconductors

The non-resonant microwave absorption (NRMA) studies in silver doped polycr ystalline Bi2Sr2Ca1Cu2O8 samples have been carried out. NRMA signal has bee n observed not only below Tc but also above Tc which is much above the fluc tuation regime when the DC magnetic field was swept from -50G to +50G throu gh 0G. Anomalous magnetic hysteresis behaviour has been observed where the forward curve lies above the return curve even at lower temperatures. The o bserved curve has been simulated by taking into consideration the sum of re versible Posses as well as irreversible losses using Dulcic and Portis mode ls. This leads to anomalous magnetic hysteresis behaviour as has been obser ved experimentally.