在基于铁的层状LaO1-xFxFeAs系统中,磁性顺序接近超导
Clarina de la Cruz1, Q Huang, J W Lynn
1Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996-1200, USA.
Nature
|May 30, 2008
概括
研究人员在LaOFeAs中发现了自旋密度波 (SDW) 顺序的直接证据,LaOFeAs是基于铁的超导体的关键母化合物. 通过兴奋剂抑制这种磁性秩序促进了超导性,类似于高温铜氧化物.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 磁力学 磁力学 是一种
背景情况:
- 高过渡温度 (高T) 铜氧化物表现出接近反铁磁的超导性.
- 稀土铁基氧化物 (ROFeAs) 也在兴奋剂时表现出超导性,但缺乏对母化合物磁性秩序的直接证据.
- 一个母化合物LaOFeAs显示出暗示磁性不稳定的异常,但缺乏直接证明自旋密度波 (SDW) 顺序的证据.
研究的目的:
- 在母化合物LaOFeAs.As中提供自旋密度波 (SDW) 磁顺序的直接实验证据.
- 研究基于铁的氧化物中结构扭曲,磁性秩序和超导性之间的关系.
- 了解反铁磁在这些材料中超导的出现中的作用.
主要方法:
- 对LaOFeAs进行了中子散射实验.
- 进行了电阻和直流磁感应度测量.
- 研究了兴奋剂对结构性和磁性特性的影响.
主要成果:
- 在155K以下,LaOFeAs从四边形对称到单对称的结构扭曲.
- 远程SDW类型的反铁磁秩序在大约137K以下发展.
- 兴奋剂抑制了结构扭曲和磁性秩序,导致超导.
- 发现超导体制与远距离有序的反铁磁基态非常接近.
结论:
- 在LaOFeAs中,SDW秩序的直接证据证实了它作为超导体的前体的作用.
- 这些发现建立了铁基超导体和高T (c) 氧化铜之间的平行,关于磁性和超导性的接近.
- 了解这种相互作用对于设计新的超导材料至关重要.
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