N. Ishikawa et al., Irradiation temperature dependence of swift heavy ion induced defects in oxide superconductor EuBa2Cu3Oy, NUCL INST B, 164, 2000, pp. 384-390
Thin films of oxide superconductor EuBa2Cu3Oy,. have been irradiated with 8
0-90 MeV I ions at various temperatures (281, 100, 50 and 12 K). To decide
the diameter and the inside-resistivity (resistivity inside the columnar de
fect), the ion-fluence dependence of electrical resistivity was measured in
-situ at 100 and 281 K. The irradiation at 281 K results in the production
of columnar defects with much higher inside-resistivity and smaller diamete
r than those produced by irradiation at 100 K. The difference in the defect
structure between these two irradiations can be explained as due to the di
fference in stability of defects primarily produced by electronic excitatio
n. The result of annealing the sample up to room temperature after irradiat
ion at 100 K supports the above explanation. The irradiation at 50 and 12 K
, which are below the superconducting transition temperature. T-c, does not
show any difference in irradiation effect from the irradiation above T-c.
Effects of irradiation at 100 K and subsequent annealing up to room tempera
ture on the Hall coefficient have also been studied. (C) 2000 Elsevier Scie
nce B.V. All rights reserved.