Energy gap in YBa2Cu3Ox determined from the data on tunnel experiments with single crystals
Al'tfeder I. B. , Volodin A.P. , Makarenko I.N. , Stishov S. M., Shubnikov A. V.
The tunnel spectra of YBa^Cu^O^ single crystals with various oxygen concentrations were studied using a scanning tunneling microscope in the orientations perpendicular to and parallel to the basal ab plane. Two gap-related structural features were observed in the tunnel spectra in the orientation at right angles to the ab plane. The plot of the energy gap Δ (χ) is similar to the plot of Tc{x). The distribution of Δ in the depth of the sample was found to be systematically nonuniform.