Comparative Analysis of the Irradiation with Medium Fluences of High-Energy Electrons and Pr Doping on the Fluctuation Conductivity of YBa2Cu3O7-δ Single Crystals

Medium-fluence fast electron irradiation (10(19) e/cm(2) to 10(20) e/cm(2)) or the changes in the praseodymium concentration in the range of 0.0 <= z <= 0.5 on the excess conductivity of YBa2Cu3O7-delta single crystals ware investigated. These can lead to a wider range of the temperature interval of excess conductivity which narrows the interval of linearity in the ab plane. At fluences 0 <= Phi <= 6.5 x 10(19) e/cm(2), there was a threefold increase in the transverse coherence length xi(c)(0) with an increase in Phi of more than four times as the praseodymium concentration increased to z approximate to 0.42. The two-dimensional-three-dimensional (2D-3D) crossover point shifted upward in temperature. Conversely, to irradiation with low fluences (Phi <= 10(19) e/cm(2)) or low praseodymium doping (z <= 0.39), irradiation with medium fluences or high praseodymium doping led to a non-monotonic dependence of xi(c)(0) on the irradiation fluence, with characteristic maxima at Phi similar to(7-8) x 10(19) e/cm(2) and z approximate to 0.42, likely due to the suppression of the superconducting characteristics.