Structural and superconducting properties of orientation-ordered ${\mathrm{Y}}_1{\mathrm{Ba}}_2{\mathrm{Cu}}_3{\mathrm{O}}_{7-x}$ films prepared by molecular-beam epitaxy

Superconducting ${\mathrm{Y}}_1{\mathrm{Ba}}_2{\mathrm{Cu}}_3{\mathrm{O}}_{7-x}$ films were produced by metal molecular-beam epitaxy with one electron beam and two thermal cells and a molecular oxygen-gas source. The films were epitaxially grown on SrTi${\mathrm{O}}_3$(100) with an $a$-axis orientation perpendicular to the plane, and $b$ and $c$ axes ordered in the plane. A sharp resistive superconducting transition with $T_c\mathrm{}(R=0\mathrm{})\mathrm{}$ at 82 K was obtained. A lower limit of the average $J_c$ in the plane is ${10}^3$ A/${\mathrm{cm}}^2$ at 77 K, 5×${10}^4$ A/${\mathrm{cm}}^2$ at 70 K, and ${10}^6$ A/${\mathrm{cm}}^2$ at 4.2 K.