Distinct itinerant spin-density waves and local-moment antiferromagnetism in an intermetallic ErPd2Si2 single crystal.
Distinct itinerant spin-density waves and local-moment antiferromagnetism in an intermetallic ErPd2Si2 single crystal.
复制标题
金属间化合物 ErPd2Si2 单晶中独特的流动自旋密度波和局部矩反铁磁性
DOI：
10.1038/srep07968
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发表时间：
2015-01-22
影响因子：
4.6
通讯作者：
Roth G
中科院分区：
文献类型：
--
作者：
Li HF;Cao C;Wildes A;Schmidt W;Schmalzl K;Hou B;Regnault LP;Zhang C;Meuffels P;Löser W;Roth G
确定磁性的性质，巡回或本地化，仍然是凝聚态科学的一个主要挑战。铁磁局域磁矩只出现在磁性绝缘体中，而巡游磁矩或多或少地与金属化合物（如掺杂铜酸盐或铁基超导体）中的局域磁矩共存，阻碍了对磁性在超导性或磁阻等现象中的作用的深入理解。本文通过中子散射区分了ErPd_2Si_2单晶中传播波矢分别为Q± =（H ± 0. 557（1），0，L ± 0. 150（1））和QC =（H ± 0. 564（1），0，L）的两种反铁磁调制，其中（H，L）为米勒指数，并建立了它们各自的温度和场相关相图。调制可以共存，但也竞争，这取决于温度或施加的场强。它们与底层晶格的耦合方式不同，尽管在同一方向上具有相关的力矩。Q±调制可以归因于局域化的4f矩，而QC与巡回导带很好地相关，这得到了我们的输运研究的支持。因此，ErPd2Si2代表了一种新的模型化合物，它显示出明显分离的巡回和本地化的时刻，证实了早期的理论预测，并提供了一个独特的平台，允许在本地化的反铁磁矩阵巡回电子行为的研究。
Identifying the nature of magnetism, itinerant or localized, remains a major challenge in condensed-matter science. Purely localized moments appear only in magnetic insulators, whereas itinerant moments more or less co-exist with localized moments in metallic compounds such as the doped-cuprate or the iron-based superconductors, hampering a thorough understanding of the role of magnetism in phenomena like superconductivity or magnetoresistance. Here we distinguish two antiferromagnetic modulations with respective propagation wave vectors at Q± = (H ± 0.557(1), 0, L ± 0.150(1)) and QC = (H ± 0.564(1), 0, L), where (H, L) are allowed Miller indices, in an ErPd2Si2 single crystal by neutron scattering and establish their respective temperature- and field-dependent phase diagrams. The modulations can co-exist but also compete depending on temperature or applied field strength. They couple differently with the underlying lattice albeit with associated moments in a common direction. The Q± modulation may be attributed to localized 4f moments while the QC correlates well with itinerant conduction bands, supported by our transport studies. Hence, ErPd2Si2 represents a new model compound that displays clearly-separated itinerant and localized moments, substantiating early theoretical predictions and providing a unique platform allowing the study of itinerant electron behavior in a localized antiferromagnetic matrix.