Abstract

The paramagnetic Meissner effect, previously observed in yttrium and bismuth cuprates, was discovered in DyRh_3.8Ru_0.2B₄, a single-phase superconductor possessing its own intrinsic magnetic subsystem. Measurement of the magnetic moment in DyRh_3.8Ru_0.2B₄ was carried out in the FC (field-cooling) and ZFC (zero-field cooling) modes: cooling in or without a magnetic field, followed by heating in the magnetic field. Appearance of a positive magnetic moment was established in the study of complex rhodium boride in the FC mode in the fields of ~20 Oe (below the first critical value). The appearance of a paramagnetic Meissner effect in DyRh_3.8Ru_0.2B₄ at fields B < B_c1 is related to the peculiarities of the magnetic subsystem behavior when the sample is cooled in the FC or ZFC modes at a temperature below the phase transition point from the paramagnetic to the ferrimagnetic state. Correlation of this anomaly with the intrinsic magnetic subsystem of the compound formed by a cluster crystal structure of the LuRu₄B₄ type is discussed. The influence of the intrinsic magnetic subsystem on the increased stability of the superconducting state is established. The presence of the intrinsic magnetic subsystem distinguishes the studied single-phase rhodium boride from other type II superconductors, which do not have a magnetic subsystem.

中文翻译：

---

磁性超导体DyRh 3.8 Ru 0.2 B 4中的顺磁迈斯纳效应

摘要

DyRh _3.8 Ru _0.2 B ₄是具有自己的固有磁子系统的单相超导体，以前在钇和铋的铜酸盐中观察到顺磁的迈斯纳效应。DyRh _3.8 Ru _0.2 B ₄中的磁矩的测量是在FC（场冷却）和ZFC（零场冷却）模式下进行的：在有磁场或无磁场的情况下冷却，然后在磁场中加热。在〜20 Oe（低于第一个临界值）的场中，以FC模式研究复合硼化铑时，确定了正磁矩的出现。DyRh _3.8 Ru _0.2中顺磁性迈斯纳效应的出现磁场B < B _c1处的B ₄与样品在FC或ZFC模式下，在从顺磁态到亚铁磁态的相变点以下的温度下冷却时，磁性子系统行为的特性有关。讨论了该异常与由LuRu ₄ B ₄型团簇晶体结构形成的化合物的本征磁子系统的相关性。建立了本征磁子系统对超导状态稳定性增加的影响。本征磁性子系统的存在将研究的单相硼化铑与其他II型超导体区分开，后者没有磁性子系统。