Two level undercut-profile substrate for filamentary YBa₂Cu₃O₇ coated conductors

A novel substrate design is presented for scalable industrial production of filamentary coated conductors (CCs). The new substrate, called 'two level undercut-profile substrate (2LUPS)', has two levels of plateaus connected by walls with an undercut profile. The undercuts are made to produce a shading effect during subsequent deposition of layers, thereby creating gaps in the superconducting layer deposited on the curved walls between the two levels. It is demonstrated that such 2LUPS-based CCs can be produced in a large-scale production system using standard deposition processes, with no additional post-processing. Inspection of the conductor cross-section reveals that the deposited superconducting layer is physically separated at the 2LUPS undercuts. Filament decoupling is also seen in maps of the remanent magnetic field and confirmed by transport measurements. (fast track communication)