Orientation control of Pt added YBa 2Cu 3O 6+ x by the directional solidification method

Abstract

The unidirectional solidification method was used in order to grow samples taking different nominal compositions of YBa 2Cu 3O 6 + x (Y123) + n% Y 2BaCuO x (Y211) ( n = 10, 30 and 50) with addition of 0.5 wt.% of Pt. One way to obtain higher J c is to grow the crystals with a− b planes orientation and crystal growth directions as close as possible. In the present study, we investigate the process to control the growth orientation. As a consequence of studying the growth orientation dependence on pulling rate and nominal compositions in the unidirectional solidification method, it was found that the combination of higher pulling rate and lower Y211 addition provided a good choice for growing single grain crystals with higher J c. The particle pushing theory offers one possibility to explain the above-mentioned results at least within the range of single grain growth conditions.