YBa2Cu3O7 films processed by CVD in high magnetic fields

In order to develop a new fabrication process using a high magnetic field, we intended to demonstrate a chemical vapour deposition technique in magnetic fields (in-field CVD). The in-field CVD apparatus was made for the first time, combining with an 11 T cryogen-free superconducting magnet. From a viewpoint of high temperature superconducting power applications, YBa2Cu3O7 films deposited on polycrystalline Ag tapes were prepared by in-field CVD process. It is found that the magnetic field in the CVD method improves the crystallinity of YBa2Cu3O7. Moreover, we found that the surface morphology of YBa2Cu3O7 outstandingly changed by the in-field CVD process, and in particular, the grain size of YBaYBa2Cu3O7 is reduced by a factor of about 10 by applying a magnetic field above a few tesla. (author)