High-Field Paramagnetic Meissner Effect in Ga-Implanted YBa2Cu3O7-delta Single Crystal

作者：Vieira V N^*; Dias F T; Gouvea C P; Pureur P; Schaf J; Hneda M L

来源：IEEE Transactions on Applied Superconductivity, 2016, 26(3): 8201504.

DOI：10.1109/TASC.2016.2533561

• HFPME
• magnetic flux compression
• superficial pinning and YBa2Cu3O7-delta

We report on dc magnetization data collected from a modified superficial pinning potential YBa2Cu3O7-delta single crystal with the goal of checking the majority contribution of the magnetic flux compression scenario to the high-field paramagnetic Meissner effect (HFPME). The additional superficial pinning centers were introduced at the YBa2Cu3O7-delta [YBCO(Ga)] single crystal surface by Ga ion beam bombardment. The field-cooled warming (M-FCW (T)), field-cooled cooling (M-FCC (T)), and zero-field-cooled (M-ZFC (T)) dc magnetizations were recorded, while magnetic fields H up to 50 kOe were applied parallel to the single crystal c-axis. M-FCW (T) and M-FCC (T) data show the usual superconductor diamagnetic response to H < 5 kOe. In contrast, when 5 kOe <= H <= 50 kOe was applied, M-FCW(T) and M-FCC (T), particularly for T << (irr)(H) (magnetic irreversibility temperature), become paramagnetic. The magnetic-field-dependent paramagnetic behavior of M-FCW (T) and M-FCC (T) is the physical signature of HFPME in superconductor materials. We contrast the HFPME observed to the YBCO(Ga) sample with that observed to a not irradiated YBa2Cu3O7-delta (YBCO) single crystal. We suggest that the enhancement of superficial pinning potential collaborates definitely to the strengthening of the magnetic flux compression scenario and consequently to the reinforcement of the HPME in YBa2Cu3O7-delta single crystals.

• 出版日期2016-4
• 单位中国计量科学研究院