TY - JOUR
T1 - A possible new vortex phase boundary in YBa2Cu3O7-δ
AU - Huang, Z. J.
AU - Xue, Y. Y.
AU - Hor, P. H.
AU - Chu, C. W.
N1 - Funding Information:
We would like to thank Drs. R.L. Meng, Y.K. Tao and H.Z. Chen for supplying the samples used in this study. This work is supported in part by the NSF Low Temperature Physics Program Grant No. DMR 86-126539, DARPA Grant No. MDA 972-88-G-002, NASA Grant No. NAGW-977, Texas Center for Su- perconductivity at the University the T.L.L. Temple Foundation.
PY - 1991/5/15
Y1 - 1991/5/15
N2 - Measurements of flux creep in melt-textured YBa2Cu3O7-δ (Y1:2:3) samples have been extended to magnetic fields up to 5.5 T and temperatures up to 85 K. In contrast to behavior at low fields and low temperatures, the decay of the magnetization is highly nonlogarithmic. At such fields and temperatures, the relative relaxation rate dlnM/dlnt changes from an essentially temperature-independent behavior to a rapid increase with temperature as the temperature and field exceed certain values. In other words, the creep barrier U(t) at a fixed observation time t starts to decrease at high temperature following the initial increase previously observed. The observations suggest the possible existence of a new phase boundary in the TH phase diagram below the irreversibility line.
AB - Measurements of flux creep in melt-textured YBa2Cu3O7-δ (Y1:2:3) samples have been extended to magnetic fields up to 5.5 T and temperatures up to 85 K. In contrast to behavior at low fields and low temperatures, the decay of the magnetization is highly nonlogarithmic. At such fields and temperatures, the relative relaxation rate dlnM/dlnt changes from an essentially temperature-independent behavior to a rapid increase with temperature as the temperature and field exceed certain values. In other words, the creep barrier U(t) at a fixed observation time t starts to decrease at high temperature following the initial increase previously observed. The observations suggest the possible existence of a new phase boundary in the TH phase diagram below the irreversibility line.
UR - http://www.scopus.com/inward/record.url?scp=0026155472&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0026155472&partnerID=8YFLogxK
U2 - 10.1016/0921-4534(91)90713-9
DO - 10.1016/0921-4534(91)90713-9
M3 - Article
AN - SCOPUS:0026155472
SN - 0921-4534
VL - 176
SP - 195
EP - 202
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
IS - 1-3
ER -