Fabrication of meander shaped RE123 LPE films for PCS materials

摘要

We have fabricated a meander shaped LPE film to realize a high electric resistance in the normal state as a persistent current switch material. A seed film on an MgO single crystalline substrate was shaped into a meander by a chemical etching method and dipped into solution for further LPE growth of RE123. The meander shaped RE123 LPE film with a long current path on the 2 inch diameter MgO substrate could be successfully grown. This phenomenon can be explained by the change of the growth mode from step growth to a nucleation limited growth on the a(b)-c plane of the crystal. This is further explained by the small step-advancing rate of the RE123 crystal on the MgO surface and above a partly dissolved MgO substrate. The film revealed a high resistance value of about 1.7 Ω at 100 K and a high Ic value of 50 A at 77 K and 0 T which is estimated to about 175 A at 20 K and 3 T.