Ion-irradiation effect on electron transport in YBCO thin films

The disorder effect on superconducting properties of thin-film YBCO nanostructures in external magnetic fields is experimentally studied. The disorder was produced by irradiation with xenon ions. The research included transport measurements of narrow bridges based on HTSC YBCO films (thickness 50 nm) in strong magnetic fields (up to 12 T). Thus, for samples with different degrees of disorder, critical dependences have been studied, i.e. the $H_{c2}(T)$ phase-transition line, the $H_{irr}(T)$ irreversibility line, etc. The dependences of the mean-free path and critical temperature on the concentration of defects created by ion irradiation have been experimentally studied. The experimental data are described using formulas obtained within the framework of well-known models, such as the Ginzburg–Landau theory, the Drude theory, and the Gorkov equations.