Near-zero-field hysteretic anomaly in microwave absorption and indication of reentrant phase in Bi2212 single crystals

Nonresonant microwave absorption are measured on Bi2212 single crystals in various hysteretic field sweep ranges with the field direction along the c- axis in liquid nitrogen temperature range. The broad peak can be interprete d by the vortex solid phase in the reentrant phase diagram. The different h ysteretic spectra depending on the field sweep range can be attributed to d ifferent vortex trapping depending on the vortex phase. (C) 2001 Elsevier S cience B.V. All rights reserved.