实验结果表明,在YBa_2Cu_3O_(7-δ)系,人为地使化学成分偏离理想配比,将引入新的小尺度缺陷并成为有效钉扎中心,使临界电流密度明显提高,且导致J_c(H)的非单调关系(即对应于磁化曲线的“鱼尾效应”).有关高温超导体中的“鱼尾效应”的起源,迄今虽有几种解释模型,但仍缺乏统一的认识,其重要原因是由于高温超导体中有效钉扎势很小而运行温度又较高, Experimental results show that in YBa_2Cu_3O_ (7-δ) system, artificially deviating the chemical composition from the ideal ratio will introduce new small-scale defects and become an effective pinning center, so that the critical current density is obviously increased, and the J_c (H) Non-monotonous relationship (ie, the “fish tail effect” corresponding to the magnetization curve.) Although the origins of the “fish tail effect” in high-temperature superconductors have so far been explained by several models, there is a lack of common understanding Due to the effective pinning potential in high-temperature superconductors and the high operating temperature,