THERMALLY-INDUCED DIMENSIONAL CROSSOVER IN SINGLE-CRYSTAL BI2SR2CACU2OX

The linear ac magnetic response of three Bi2Sr2CaCu2Ox single crystals with various doping states was investigated with a miniature two-coil mutual inductance technique in magnetic fields parallel to the c axis . The dissipation peak appeared right below T-c, and a drop in dissipa tion was observed at a frequency-independent temperature T-D together with an increase in shielding signal, upon field cooling the sample. T he observed frequency-independent feature can be understood as a conse quence of the thermally induced dimensional crossover.