Influence of electron irradiation on fluctuation conductivity and pseudogap in YBa₂Cu₃O_7?? single crystals

The effect of electron irradiation with the energy 2.5 MeV on temperature dependences resistivity an optimally doped $YBa_2Cu_3O_{7-\delta}$ single crystal has been studied. both fluctuation conductivity $\sigma^\prime(T)$ and pseudogap $\Delta^*(T)$ dose $\phi$ have calculated within local pair model. Here we show that increase in $\phi$, value $\rho(300 K)$ increases linearly, while $T_c$ decreases linearly. Concurrently, $\rho{100 K}$ nonlinearly, demonstrating a feature for $\phi_3$ = 4.3 10$^{18}$ e/$cm^2$, which is also observed number other dose-dependent parameters.Regardless dose, range from up to $T_{01}$, obeys classical theories Aslamazov$-$Larkin Maki$-$Thompson, 3D$-$2D crossover increasing temperature. $T_0$ makes it possible determine coherence length along $c$-axis, $\xi_c(T)$, by $\approx 3$ times under irradiation. Furthermore, superconducting fluctuations above noticeably increases.At 0, dependence typical crystals containing pronounced twin boundaries maximum at $T_{pair}$ ~ 120 K distinct minimum $T T_{01}$. It was determined first time shape changes strongly becomes same as very low opening $T^*$ reduced $T_{pair}$, $T_c(\phi)$ there are no singularities.