Transport properties, phase transition, and recovery near 200 K of proton-irradiated Y${\mathrm{Ba}}_2$${\mathrm{Cu}}_3$${\mathrm{O}}_7$ thin films

Irradiation of thin Y${\mathrm{Ba}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_7$ films with protons at 4.2 and 77 K causes distinct changes of the resistivity ${\rho }_0$, $T_c$, the transition width $\delta T_c$, and the formation of new phases in different fluence regions. At low fluences, $T_c$ and $\delta T_c$ are not affected, while ${\rho }_0$ and the thermal part of the resistivity, ${\rho }_{\mathrm{th}}$, increase. This behavior is quite different from that of previous "high-$T_c$" superconductors. At large fluences, a semiconducting phase developed, revealing a dose-dependent activation energy. About 60% of the irradiation-induced changes recover during annealing above 200 K.