The temperature dependence of the self-field and in-field critical current densities J_c(T) was investigated in YBa₂Cu₃O_7–δ thin films containing a high density of nanoprecipitates. The self-field J_c(T) and in-field J_c(T) were both approximated by J_c(T) ∼ (1 – T/T_c)^m (1 + T/T_c)², where the index m was mostly 2.0–2.6 in moderate magnetic fields (µ₀H = 0.5–1 T, // c-axis), but m was smaller (1.5–1.8) in self-fields. This phenomenon can be explained by the assumption that the self-field J_c is determined by the flux pinning by relatively large nanoprecipitates, which is supported by simple theoretical calculations of the elementary pinning force f_p due to the core pinning interaction. The self-field J_c is estimated to be proportional to 1/λ³, where λ is the penetration depth. This relationship can successfully explain the previously observed inverse correlation between the self-field J_c and the surface resistance R_s that is supposed to be proportional to λ³.

在含有高密度纳米沉淀物的YBa ₂ Cu ₃ O _7-δ薄膜中研究了自场和场内临界电流密度J _c ( T ) 的温度依赖性。自场J _c ( T ) 和场内J _c ( T ) 均由J _c ( T ) ∼ (1 – T / T _c ) ^m (1 +  T / T _c ) ²近似，其中索引米在中等磁场（μ ₀ H  = 0.5-1 T，// c轴）中主要为 2.0-2.6，但在自场中m较小（1.5-1.8）。这种现象可以通过以下假设来解释：自场J _c由相对较大的纳米沉淀物的通量钉扎决定，这得到了由于核心钉扎相互作用导致的基本钉扎力f _{p的简单理论计算的支持。}自场J _c估计与 1/ λ ³成比例，其中λ是穿透深度。这种关系可以成功地解释先前观察到的自场J _c和表面电阻R _s之间的反相关，表面电阻 R s应该与λ ³成正比。