The cascade defects which were generated by the ion bombardment (18MeV Fe8+, 1012/cm2) of single crystals were investigated by means of transmission electron microscopy. The sizes and distributions of the defects were quantitatively measured by using an image analysis method. These parameters were found to be very influential in enhancing the critical current density. The relationship between the irradiation conditions and the cascade defects could be used to produce flux-pinning centers of optimum size. The critical current density and cascade defects that were produced by 18, 14, and 10MeV Fe-ion bombardment along the c-axis were also studied.

Y.Sasaki, W.L.Zhou, Y.Ikuhara, H.Saka: Materials Transactions, 1996, 37[4], 902-6