Effects of Sn-doping on JC– B properties and crystalline structure for YBCO films by advanced TFA-MOD method

Abstract

To improve J C properties in a magnetic field ( J C– B) of YBa 2Cu 3O 7− δ (YBCO) films by a TFA-MOD (trifluoroacetates metal organic deposition) method, we fabricated YBCO films with SnO 2-doping as artificial pinning centers and investigated the superconducting properties and the crystalline structures. TFA-MOD is expected as a cost-effective method with a non-vacuum system to fabricate YBCO films with high superconducting properties. However, YBCO films have problems that J C decreases in a magnetic field ( B). In this study, the TFA solutions with SnO 2 for pinning centers were used as starting materials. In the transmission electron microscope image, existence of second phase particles with size of 20–30 nm has been observed in the YBCO film. These nano-particles contained Sn-element and distributed randomly in the film. The J C/ J C (self field) values of the SnO 2-doped YBCO films were enhanced in all magnetic field angles. Therefore it is considered that 3D pinning centers of Sn-compounds were introduced into YBCO film.