Formation of YBa2Cu3O7−y/BaTiO3 multistructures by pulsed laser deposition for high-temperature superconducting device applications

Abstract

The formation of YBa₂Cu₃O_7−y(YBCO)/BaTiO₃(BTO)//SrTiO₃(STO) (100) and BTO/ YBCO//STO(100) bilayer structures is demonstrated for the construction of a superconductor ferroelectric field transistor. The resulting films of the bilayers have highly c‐axis oriented structure. Epitaxial YBCO films formed on the BTO//STO(100) have a zero resistance temperature of 88.9 K. The surface morphology of the epitaxial BTO films on the YBCO//STO is very smooth with a mean surface roughness of 32 Å. Moreover, the Au/BTO/YBCO structures have been fabricated, and the dielectric constant and remanent polarization of BTO layer are obtained to be 180 and 3.5 μC/cm² at 77 K, respectively.