[3H01-06] Irradiation Behavior

[3H02] Evaluation of irradiation effects on high entropy cuprate superconductors

*Kota Sakurai¹, Naoko Oono¹, Aichi Yamashita², Yoshikazu Mizuguchi², Kiyohiro Yabuuchi³, Okinobu Hashitomi³ (1. Yokohama Natl. Univ., 2. Tokyo Metropolitan Univ., 3. Kyoto Univ.)

Keywords:high entropy, superconducting magnet, irradiation defect, flux pinning

Degradation of properties of superconductors due to neutron irradiation is an issue in fusion reactors. On the other hand, it is found that high-entropy alloys (HEAs) have irradiation-resistance. We expect that high entropy superconductors including several RE(rare earth) elements at RE site of REBCO may have similar effects. Polycrystalline specimens of YBa₂Cu₃O_7-δ(YBCO) , Y_0.39Sm_0.30Eu_0.31Ba₂Cu₃O_7-δ(ME-REBCO), and Y_0.18La_0.24Nd_0.14Sm_0.14Eu_0.15Gd_0.15Ba₂Cu₃O_7-δ(HE-REBCO) were irradiated with 1 MeV He⁺ ions up to 70 mdpa. SQUID magnetization measurements suggest that only HE-REBCO exhibits an enhanced property. The TEM observations showed that the irradiation defects in HE-REBCO tended to be small. This result suggested that the small volume fraction and the magnetic flux pinning effect influence the properties positively.