Magnetic hysteresis M(H) and magnetic relaxation M(t) results on Pr-doped single-crystal Bi2Sr2Ca0.89Pr0.11Cu2O8+δ with optimum Tc = 88 K are reported. Superconducting H-T phase diagram with applied field parallel to single-crystal c-axis indicates that in the mixed state the anomalous second peak field and its onset field H2p/Hon varies from 900/800 G at 15 K to 210/85 G at 40 K with a plateau around 20-30 K. Low-field magnetic relaxation M(t) data near H2p/Hon indicates a distinct change of flux creep behavior. For H<Hon, the relaxation mechanism follows the collective creep model M(t) = M0[1+(μkBT/U0)ln(t/t0)]-1/μ and crosses to the vortex glass model M(t) = M0(t/t0)1/[1-(U(0)/k(B)T)] when H>Hon. Such a crossover behavior implies a change in vortex coupling mechanism from vortex quasi-lattice to entangled vortex glass.
|頁（從 - 到）||931-932|
|期刊||Physica B: Condensed Matter|
|出版狀態||已發佈 - 2000 6月 1|
|事件||Yamada Conference LI - The International Conference on Strongly Correlated Electron Systems (SCES '99) - Nagano, Jpn|
持續時間: 1999 8月 24 → 1999 8月 28
ASJC Scopus subject areas