Tuesday, 08/19/08

Session Title:	Flux Pinning and Dynamics II - Engineered Pinning Arrangements
Session Chairs:	Paul Barnes, Air Force Research Laboratory, Wright-Patterson AFB & Takanobu Kiss, Kyushu University
Paper Number:	2MPD03
Start Time:	10:00am
Session Type:	Poster

Difference between BaSnO3 and BaZrO3 nano-rods for c-axis correlated pinning properties in REBa2Cu3Oy M. Namba, S. Awaji, K. Watanabe, HFLSM, IMR, Tohoku Univ.; H. Kai, S. Yasunaga, M. Mukaida, Kyushu Univ.

The introduction of the c-axis correlated disorder is a promising technique for the improvement of the critical current density Jc at B//c for the REBa2Cu3Oy (RE123) films and tapes. In particular, for the RE123 film with BaZrO3, the columnar shaped BaZrO3 precipitate, called nano-rods, can be introduced as the c-axis correlated pinning centers. Recently, it is found that the BaSnO3 nano-rods can be introduced in RE123 films with a slight decrease of Tc in comparison with BaZrO3. In order to understand the vortex pinning state by BaSnO3 nano-rods, the angular dependence of Jc was measured in detail for Er123 films with BaSnO3 prepared by pulsed laser deposition. The peak at the parallel external field to the c-axis (B//c) in the angular dependence of Jc appears in a wide magnetic field region from the low magnetic field to the irreversible field at various temperatures, although it disappears in a high field region in the case of the BaZrO3 nano-rods. Hence, we found that the c-axis correlated pinning properties for two kinds of nano-rods are different each other at the high magnetic field. The different behavior of the c-axis correlated pinning may be related with the alignment of the nano-rods.