کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1874553 | 1530966 | 2014 | 4 صفحه PDF | دانلود رایگان |
The nano-scale spatial gap distributions on apical-fluorine multi-layered cuprate superconductors Ba2Ca4Cu5O10(O1-x, Fx) (F0245, Tc = 70 K) are investigated by scanning tunneling microscopy/spectroscopy (STM/STS). The STM image shows randomly-distributed bright spot structures, which are assigned to the non-replaced apical oxygen. The dI/dV tunnel spectra show the coexistence of two kinds of the gap structures. The magnitudes of these gaps at 4.9 K are about ΔS ∼25 meV and ΔL ∼78 meV, respectively. The ΔL map shows the inhomogeneous distribution with the characteristic length of ∼1 nm. The smaller ΔL gap regions tend to locate at the bright-spot positions, indicating that the apical oxygen causes reduction of ΔL. These results are consistent with the well known relation between the carrier doping level and macroscopically observed gap size.
Journal: Physics Procedia - Volume 58, 2014, Pages 78-81