Ion-beam-induced destruction of superconducting phase coherence in ${\mathrm{YBa}}_2$${\mathrm{Cu}}_3$${\mathrm{O}}_{7\mathrm{-}\mathrm{\delta }}$

We have explored the effects of ion beam irradiation on the electrical and structural properties of superconducting thin films of ${\mathrm{YBa}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_{7\mathrm{-}\mathrm{\delta }}$. Damage created by nuclear-energy loss processes degrades the superconducting transitions. Data from resistance measurements as well as from Rutherford backscattering and channeling measurements suggest that ion bombardment is not changing the volume fraction of superconducting material substantially. Instead, it appears that islands of good superconductor are becoming progressively decoupled, destroying the phase coherence.