Good-quality melt-textured YBa2Cu3O7-x materials with Y2BaCuO5 nonsupercond
ucting inclusions were irradiated with 2 GeV gold ions in order to produce
a surface layer with columnar defects. The final goal is to gain a basic un
derstanding of the role of the surface columnar defects in determining thos
e magnetic properties of the materials that are related to the vortex confi
nement. The particle energy and the sample thickness were chosen in such a
way that the percentage of irradiated volume is about 10%. In the paper the
intrinsic structure and the damage morphology were analysed by means of tr
ansmission electron microscopy studies in both cross-section and plan-view
geometry. As a result, the columnar defect density, size and shape were obt
ained. The irradiation produces parallel heavily damaged tracks whose diame
ter is between 3 and 6 nm. The overlapping of some columnar defects was hig
hlighted and had to be taken into account to understand the superconducting
properties of irradiated samples. The defects affect an implanted layer of
about 50 mu m. The measured thickness coincides, within the experimental e
rrors, with the thickness calculated by means of the Monte Carlo TRIM simul
ations.