Understanding the mechanisms that limit the current transport in granular iron-based superconductors is necessary to unlock their potential for magnet applications. This paper reports the transport critical current surface I C ( T,H ) of powder-in-tube Ag/Ba 1−x K x Fe 2 As 2 tapes densified by flat rolling and uniaxial hot pressing. We investigate the amplitude of the isothermal- I C ( H )-curve magnetic hysteresis, which is a marker for the electrical connectivity between superconducting grains. This allows us to demonstrate that, in spite of an improved connectivity, the percolative path through weakly linked grains continues to play a role in the I C properties of hot-pressed conductors. The limitations to the current transport due to weak links depend on the orientation of the magnetic field and are more severe when H is on the tape plane. This finding provides a justifi...

中文翻译：

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致密化的Ag包覆的Ba 1-x K x Fe 2 As 2带的电流输运，磁性和元素性质

必须了解限制粒状铁基超导体中电流传输的机制，才能释放其在磁体应用中的潜力。本文报道了扁粉轧制和单轴热压致密化的管内粉Ag / Ba 1-x K x Fe 2 As 2带的输运临界电流表面IC（T，H）。我们研究了等温IC（H）曲线磁滞的幅度，该幅度是超导晶粒之间电连通性的标志。这使我们能够证明，尽管连通性得到了改善，但通过弱连接晶粒的渗透路径仍在热压导体的IC特性中发挥作用。弱链接对电流传输的限制取决于磁场的方向，并且当H在磁带平面上时更为严格。