High critical currents in strained epitaxial YBa2Cu3O7−δ on Si

Abstract
Epitaxial YBa2Cu3O7−δ (YBCO) films were grown on Si (100) using an intermediate buffer layer of yttria‐stabilized zirconia. Both layers are grown via an entirely in situ process by pulsed laser deposition. All films consist of c‐axis oriented grains as measured by x‐ray diffraction. Strain results from the large difference in thermal expansion coefficients between Si and YBCO. Thin (Tc (R=0) is 86–88 K with a transition width (ΔTc) of 1 K. Critical current densities of 2×107 A/cm2 at 4.2 K and 2.2×106 A/cm2 at 77 K have been achieved.