Irreversibility Field and c-Axis Correlated Pinning in High-$J_{c}$ SmBCO Films

摘要

A high critical current density $J_{c}$ at 77.3 K and a high irreversibility field for ${rm B}parallel {rm c}$ were achieved for low-temperature-growth processed ${rm SmBa}_{2}{rm Cu}_{3}{rm O}_{7}$ (LTG-Sm123) films. Transport properties of the LTG-Sm123 films with high $J_{c}$ were measured in high magnetic fields up to 17 T. We found a small enhancement of the irreversibility field due to the c-axis correlated pinning. We also observed the large peak for ${rm B}parallel {rm c}$ in a low field region below 1 T and 77.3 K. Those behaviors are originated with the c-axis correlated pinning. The peak at ${rm B}parallel {rm c}$ decreases in a low field region but increases again above 3 T with increasing a magnetic field. These $J_{c}$ behaviors are considerably related with the enhancement of irreversibility field. From experimental results obtained in this study, we proposed new pinned glass states near the irreversibility field.