Effect of Ta irradiation on microstructure and current carrying properties of YBCO coated conductors with element doping

In the present work, we study the change of microstructural and current carrying properties of the YBa2Cu3O7-delta (YBCO) coated conductors (CCs) doped with mixed elements of Ta, Zr, Hf, Mn, and Sn after the irradiation of 1.9 GeV Ta ions. Magnetic property measurement system measurement was applied to study the current carrying properties of the irradiated YBCO CCs. The critical transition temperature (T-c,T-on) decreases by 0.5 K as the ion fluence reaches 5.0 x 10(10) ions/cm(2). It is revealed that for the irradiated samples with the fluence higher than 1.0 x 10(8) ions/cm(2), their negative magnetization is enhanced pronouncedly as the applied temperature is lower than T-c,T-on, which implies that there are more antimagnetic phases being resistant to magnetic fields in these irradiated samples. Besides, the critical current density (J(c)) and the pinning force (F-p) increase with the increase of the Ta ion fluence. Particularly for the case of the fluence more than 5.0 x 10(10) ions/cm(2), J(c) reached 8.74 x 10(6) A/cm(2) at 1 T and 30 K and F-p reached 8.84 x 10(10) N/m(3) at 1 T and 30 K. As a consequence, the J(c) value of the studied YBCO CCs is improved by 4.4 times at 1 T and 30 K compared with the value of 1.98 x 10(6) A/cm(2) of the primitive sample. Moreover, the sectional microstructures of the YBCO superconducting layer observed by a field emission transmission electron microscope show the columnar defects with the size of about 9 nm form in the doped YBCO films after the irradiation, confirming traces of continuous latent tracks exist as the evidence of effective mixed-pinning landscapes. (C) 2021 Author(s).

Automated summary

The research shows that the negative magnetization of the YBCO coated conductors is enhanced after irradiation with tantalum ions, leading to an increase in critical current density and pinning force. The critical current density of the YBCO CCs is improved by 4.4 times at 1 T and 30 K compared with the primitive sample. The microstructures of the YBCO superconducting layer reveal the presence of columnar defects with effective mixed-pinning landscapes.