TRANSPARENCY OF THE AB PLANES OF BI2SR2CACU2O8-FIELDS(DELTA TO MAGNETIC)

A sample composed of many Bi2Sr2CaCu2O8+delta single crystals was cool ed to 2 K in a magnetic field of 100 G at 45 degrees from the c axis. Muon-spin-rotation measurements were made for which the polarization w as initially approximately in the ab plant. The time dependent polariz ation components along this initial direction and along the c axis wer e obtained. Cosine transforms of these and subsequent measurements wer e made. Upon removing the applied field, still at 2 K, only the c axis component of the field remained in the sample, thus providing microsc opic evidence for extreme 2D behavior for the vortices even at this te mperature.