TY - JOUR
T1 - Planar tunneling spectroscopy of Y1-xPrxBa2Cu3O7 thin films as a function of crystallographic orientation
AU - Covington, M.
AU - Greene, L. H.
PY - 2000/11/1
Y1 - 2000/11/1
N2 - We present a systematic study of the charge transport and quasiparticle tunneling properties of Y1-xPrxBa2Cu3O7 thin films. Pr doping increases the resistivity along the copper oxide planes and suppresses the superconducting critical temperature Tc, ultimately inducing a superconductor-insulator transition. The tunneling conductance is reproducible and correlated with the crystallographic film orientation. The crystallographic dependence can be divided into two distinct categories: Tunneling into (001)-oriented (c-axis) films and tunneling into (100)-, (110)-, and (103)-oriented (ab-oriented) films. c-axis tunneling data exhibit a conductance dip at zero bias and a broad temperature-dependent peak over ∼15-40 mV that decreases in magnitude but stays fixed in energy for increasing Pr doping levels, ab-plane tunneling data exhibit a zero-bias x conductance peak and a gaplike feature at an energy that scales roughly linearly with Tc for x=0.0, 0.2, and 0.4. When x=0.5, the resistivity is not linear in temperature and a zero-bias conductance dip is observed. The background conductance that ensures conservation of states in the low-temperature ab-plane data exhibits temperature- and doping-dependent structure over ∼15-40 mV that is very similar to the peak observed in c-axis tunneling. Finally, analysis of the temperature and magnetic field dependence of the zero bias conductance peak indicates that states are conserved to within ∼20%, supporting its interpretation as a feature of a superconducting density of states.
AB - We present a systematic study of the charge transport and quasiparticle tunneling properties of Y1-xPrxBa2Cu3O7 thin films. Pr doping increases the resistivity along the copper oxide planes and suppresses the superconducting critical temperature Tc, ultimately inducing a superconductor-insulator transition. The tunneling conductance is reproducible and correlated with the crystallographic film orientation. The crystallographic dependence can be divided into two distinct categories: Tunneling into (001)-oriented (c-axis) films and tunneling into (100)-, (110)-, and (103)-oriented (ab-oriented) films. c-axis tunneling data exhibit a conductance dip at zero bias and a broad temperature-dependent peak over ∼15-40 mV that decreases in magnitude but stays fixed in energy for increasing Pr doping levels, ab-plane tunneling data exhibit a zero-bias x conductance peak and a gaplike feature at an energy that scales roughly linearly with Tc for x=0.0, 0.2, and 0.4. When x=0.5, the resistivity is not linear in temperature and a zero-bias conductance dip is observed. The background conductance that ensures conservation of states in the low-temperature ab-plane data exhibits temperature- and doping-dependent structure over ∼15-40 mV that is very similar to the peak observed in c-axis tunneling. Finally, analysis of the temperature and magnetic field dependence of the zero bias conductance peak indicates that states are conserved to within ∼20%, supporting its interpretation as a feature of a superconducting density of states.
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U2 - 10.1103/PhysRevB.62.12440
DO - 10.1103/PhysRevB.62.12440
M3 - Article
AN - SCOPUS:0034312687
SN - 0163-1829
VL - 62
SP - 12440
EP - 12454
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 18
ER -