Rare Earth Geometrically Frustrated Magnets

稀土几何受挫磁铁

• 批准号: 1341793
• 负责人: Peter Schiffer
• 金额: $ 36.5万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-01-01 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1341793&HistoricalAwards=false
• 关键词: Rare; Earth; Geometrically; Frustrated; Magnets

****Technical**** The goal of this research program is to investigate rare earth geometrically frustrated magnets. These are materials in which the interactions between the moments associated with rare earth ions compete with each other due to the particular geometry of the magnetic sublattice. The frustration in these materials leads to unusual low temperature states in which the interaction energies cannot all be simultaneously minimized, such as spin liquids and spin ices. The research will explore new geometrically frustrated magnetic materials and will have a special focus on the spin ice states in which exotic monopole-like excitations have been observed. The experiments will focus on magnetic susceptibility studies but will also include a number of other techniques. The research will be conducted in close collaboration with material scientists and chemists who can provide unique and important samples of new materials. Students involved in the research will participate in traditional and cutting edge training in a wide range of experimental techniques that will prepare them for careers in academe, industry or government.****Non-technical****This is a research program into the physics of a group of materials known as rare earth geometrically frustrated magnets. The magnetic atoms in these materials are unable to direct their magnetic axes (known as the magnetic moments) in a unique way to minimize the combined energy of their collective state. The underlying cause of this inability to minimize the energy is the geometrical arrangement of the magnetic atoms within the materials, and this geometrical arrangement makes these materials excellent models for a wide range of other complex systems which are similarly 'frustrated'. In particular, this research program will probe the nature of special materials known as spin ices, in which the disorder of the magnetic moments mimics the behavior of frozen water and acts as an ideal model system for testing basic understanding of collective behavior of many other systems. The research will also probe other new materials in this class obtained through substituting different elements in the chemical formulae, and looking for various novel behavior that they often exhibit. Understanding these magnetic materials has implications for other systems as diverse as superconducting junction arrays and glasses, and may also provide insight into computational algorithms. The principal investigator has an extensive record of working with a diverse students and involving graduate students and undergraduates in every stage of the research process. Students involved in this research program will participate in traditional and cutting edge training in a wide range of experimental techniques that will prepare them for careers in academe, industry or government.

****技术****该研究计划的目的是研究稀土几何沮丧的磁铁。 这些材料是，由于磁性sublattice的特殊几何形状，与稀土离子相关的矩之间的相互作用之间的相互作用相互竞争。这些材料的挫败感导致相互作用能量不能同时最小化，例如旋转液体和旋转冰。 该研究将探索新的几何沮丧的磁性材料，并将特别关注旋转冰状态，在该状态下观察到异国情调的单极样激发。这些实验将集中在磁敏感性研究上，但还将包括许多其他技术。 这项研究将与可以提供新材料样本的物质科学家和化学家密切合作进行。参与研究的学生将参加各种实验技术的传统和尖端培训，这些技术将为学术界，工业或政府的职业做好准备。这些材料中的磁原子无法以独特的方式指导其磁轴（称为磁矩），以最大程度地减少其集体状态的合并能量。无法最大程度地减少能量的根本原因是材料中磁原子的几何布置，并且这种几何布置使这些材料为其他类似“沮丧”的其他复杂系统的绝佳模型提供了出色的模型。特别是，该研究计划将探测特殊材料的性质，称为自旋冰，其中磁矩的障碍模拟了冷冻水的行为，并充当了测试许多其他系统集体行为的基本理解的理想模型系统。 这项研究还将通过替换化学公式中的不同元素而获得的该类别中的其他新材料，并寻找它们经常表现出的各种新型行为。了解这些磁性材料对其他系统的影响，例如超导连接阵列和眼镜，也可能提供对计算算法的见解。首席调查员在研究过程的每个阶段都与多元化的学生一起工作，并参与研究生和本科生。 参与该研究计划的学生将参加各种实验技术的传统和尖端培训，这将使他们为学术界，工业或政府的职业做好准备。