A -Axis—Oriented YBa ₂ Cu ₃ O ₇ /PrBa ₂ Cu ₃ O ₇ Superlattices

Abstract

A modulated structure has been fabricated from high transition temperature superconductors where the individual CuO 2 planes are composed of alternating superconducting and insulating strips. This structure is made by growing a -axis—oriented YBa 2 Cu 3 O 7 /PrBa 2 Cu 3 O 7 superlattices by 90° off-axis sputtering on (100)SrTiO 3 and (100)LaAlO 3 substrates. Superlattice modulation is observed to a modulation wavelength of 24 angstroms (12 angstroms—YBa 2 Cu 3 O 7 /12 angstroms—PrBa 2 Cu 3 O 7 ), both by x-ray diffraction and by cross-sectional transmission electron microscopy. Rutherford backscattering spectroscopy indicates a high degree of crystalline perfection with a channeling minimum yield of 3 percent. Quasi—one-dimensional conductivity should be obtainable in these structures.