Preparation of Double-Sided MgO Template for YB2Cu3O7-δ Coated Conductors

Reducing production cost and upgrading current capacity are the key issues for the commercialization of YB
₂
Cu
₃
O
_7-δ
(YBCO) high-temperature superconducting coated conductors. In this paper, a novel double-sided ion-beam-assisted deposited (IBAD) MgO template has been proposed and introduced for the deposition of YBCO coated conductors on both sides, which contributes significantly to the performance improvement and production cost cutting. In this template, chemical solution derived amorphous Y
₂
O
₃
layer was coated on untreated hastelloy tapes to obtain nanometer-level flatted surface with root-mean-square roughness values of 0.8 and 0.5 nm (5 μm × 5 μm area) for each side, respectively. Based on the smooth surface, double-sided IBAD-MgO and homoepitaxial MgO films were deposited on the Y
₂
O
₃
coatings by a two-step process. The biaxial textures of meter-long double-sided MgO tape showed ω-scans of (200) MgO and Φ-scans of (220) MgO yield full width at half maximum values of 2.5°-3° and 4.5°-6°for one side, respectively, as well as 2.6°-3.2° and 5.6°-6.5° for the other side. Finally, the double-sided YBCO films deposited on the LaMnO
₃
buffered MgO template achieved a high-transition temperature of 90 K and an overall critical current of 290 A/cm at self-field (110 and 180 A/cm for each side).