Applied superconductivity 1997, vols 1 and 2 issue:158 pages:1591-1594
We have studied the influence of columnar defects, created by heavy-ion (Kr) irradiation, on the superconducting critical parameters of single crystalline (YxTm1-x)Ba2Cu3O7. Superconductivity has not been deteriorated for irradiation fluences up to 6.10(11) ions/cm(2). Magnetisation measurements in pulsed fields up to 52 T in the temperature range 4.2 - 90 K have revealed that both critical current J(c)(H,T) and irreversibility field H-irr(T) are strongly enhanced. Thus, due to the strong pinning of flux lines by these linear defects, the superconducting critical parameters exceed the ones associated with the defect structures present in the unirradiated material. The field range and magnitude of the J(c)(H,T) and H-irr(T) enhancement are dependent on the irradiation dose.