Fermi-Liquid and Nonfermi-Liquid Properties in Weakly Hybridized 4f Intermetallic Compounds

弱杂化 4f 金属间化合物的费米液体和非费米液体性质

• 批准号: 9624778
• 负责人: Ward Beyermann
• 金额: $ 25.47万
• 依托单位: University of California-Riverside
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-05-01 至 2000-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9624778&HistoricalAwards=false
• 关键词: Fermi; Liquid; Nonfermi; Properties; Weakly

9624778 Beyermann This project is an experimental investigation of predictions of theories based on an antiferromagneticaly coupled spin-spin interaction between the electrons. The project is divided into three parts. The first part deals with the low-temperature thermodynamic and transport properties in prasedymium systems where the lowest crystal electric-field level of the localized 4f electrons has only quadrupolar, rather than magnetic, internal degrees of freedom. The evolution of the correlated-electron ground state in weakly hybridizing prasedymium intermetallic compounds is studied in the second part. The last part seeks to determine how the renormalized ground state at low temperatures changes under the influence of an applied magnetic field large enough to suppress the magnetic Kondo interaction. This part of the research will be conducted at the National High Magnetic Field Laboratory using pulsed magnetic fields up to 50 T. The results are expected to provide an important understanding of the correlations associated with the low-temperature hybridization of magnetic and quadrupolar states with the conduction electrons. %%% The PI investigates the magnetic and electrical properties of rare earth-intermetallic systems with unusual ground states. Correlated electron behavior in praseodymium-intermetallic compounds will be studied. Praseodymium is uniquely positioned to act as a logical intermediary between the strongly hybridizing cerium and the purely trivalent heavier rare earths. The observation of this behavior in certain systems with unique crystal-electric-field ground states would indicate a new interaction between the 4f orbitals and the conduction electrons. Applied magnetic fields also significantly effect these ground states, the low-temperature properties will be investigated using pulsed fields that are large enough to greatly modify the correlated behavior. This project is a collaboration between three investigators at three different institutions. Sample preparation and basic characterization will be performed at Ames Laboratory. Once suitable compounds are made, they will be sent to UC Riverside for low field magnetic and electrical measurements down to ~50 mK and to the National High Magnetic Field Laboratory at Los Alamos for high-field measurements up to 50 T. ***

小行星9624778 这个项目是对理论预测的实验研究 基于 对 反铁磁 耦合 电子之间的自旋-自旋相互作用该项目分为三个部分。第一部分研究了晶体电场最低的Prasedymium体系的低温热力学和输运性质 定域4f电子能级 具有 只有四极，而不是磁性，内部自由度。 演变 的 关联电子基态 在 第二部分研究了弱杂化镨金属间化合物。 最后一部分试图确定如何重整化基态在低温下的变化的影响下施加的磁场足够大，以抑制磁近藤相互作用。 这部分研究将在国家强磁场实验室使用高达50 T的脉冲磁场进行。 这些结果有望为理解磁性和四极态与传导电子的低温杂化相关性提供重要的参考。 PI研究具有不寻常基态的稀土金属间化合物系统的磁性和电气特性。 研究镨金属间化合物中的相关电子行为。 镨是唯一的定位，作为一个逻辑中间体之间的强杂化铈和纯三价重稀土。在某些具有独特晶体电场基态的系统中观察到这种行为，表明4f轨道和传导电子之间存在新的相互作用。 施加的磁场也会显著影响这些基态，将使用足够大的脉冲场来研究低温特性， 极大地改变了相关行为。 该项目是三个不同机构的三名研究人员之间的合作。样品制备和基本表征将在艾姆斯实验室进行。 一旦制备出合适的化合物，它们将被送到UC滨江进行低至~50 mK的低场磁场和电学测量，并被送到位于洛斯阿拉莫斯的国家高磁场实验室进行高达50 T的高场测量。 ***