Abstract
This paper reports a study of the nature and systematic variation of radiation damage to cuprate superconductors caused by several-hundred-MeV heavy ions. While irradiation of with 300-MeV and 276-MeV ions produces columns of amorphous material along the ion trajectories, such defects are only created occasionally during irradiation with 236-MeV and not induced with 182-MeV . A comparative study of the defect formation in and oxygen-reduced and ozone-treated , shows that the degree of the radiation damage by the heavy ions depends on (a) the rate at which ions lose their energy in the target; (b) the crystallographic orientations with respect to the incident ion beam; (c) thermal conductivity and chemical state (oxygen concentration for ) of the sample; and (d) the extent of preexisting defects in the crystal. A theoretical model based on ion-induced localized melting and the effects of anisotropic thermal conductivity of these materials provides a basis for understanding the size and shape of the amorphous tracks. Measurements of the superconducting properties of - and -irradiated thin films show a universal linear scaling between the fractional areal damage versus the superconducting transition temperature and the normal-state resistivity.
- Received 1 April 1993
DOI:https://doi.org/10.1103/PhysRevB.48.6436
©1993 American Physical Society