Irreversibility Field and c-Axis Correlated Pinning in High-Jc SmBCO Films

A high critical current density J_c at 77.3 K and a high irreversibility field for B par c were achieved for low-temperature-growth processed SmBa₂Cu₃O₇ (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 B par 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 B par 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.