Retardation of the Magnetic Relaxation in High-Temperature Superconductors Near a Ferromagnet
Retardation of the Magnetic Relaxation in High-Temperature Superconductors Near a Ferromagnet
复制标题
铁磁体附近高温超导体磁弛豫的延迟
DOI：
10.1007/s10948-010-1039-7
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发表时间：
2011
影响因子：
1.8
通讯作者：
M. Zakharov
中科院分区：
文献类型：
--
作者：
B. Smolyak;G. Ermakov;M. Zakharov
本文研究了高温超导块材中磁通量的蠕变。当超导体靠近铁磁体时，磁弛豫被延迟。延迟效应的大小取决于磁化的顺序和超导体与铁磁体的接近程度。当超导样品首先被磁化，然后靠近铁磁体时，磁弛豫被完全抑制。这种效果的解释进行了讨论。被磁化后，铁磁体会产生自己的磁场。当铁磁体场穿过圆盘样品的平面进入圆盘样品时，铁磁体场感应出屏蔽电流，该电流与捕获磁通量时产生的电流相反地循环。结果，由于相反的驱动力可以作用在涡流的不同部分上，所以磁结构的稳定性急剧提高。
The creep of a magnetic flux trapped in a bulk high-temperature superconductor has been studied. It has been found that the magnetic relaxation is retarded when the superconductor is placed near a ferromagnet. The value of the retardation effect depends on the sequence of magnetization and the approach of the superconductor to a ferromagnet. The magnetic relaxation is fully suppressed when a superconducting sample first is magnetized and then is brought close to a ferromagnet. An interpretation of this effect has been discussed. Being magnetized, a ferromagnet produces its own magnetic field. While penetrating into a disk sample through its planes, the ferromagnet field induces screening currents, which circulate oppositely to the current that arises upon trapping of the magnetic flux. As a result, the stability of the magnetic structure is sharply improved since opposite driving forces can act on different sections of the vortices.