CAREER: Synthesis, Characterization and Physical Properties of Pr-Based Heavy Fermions

近年来，对Ce基重费米子化合物中量子相变（QPT）的研究改变了我们对磁性和超导性的理解。这个由固态和材料化学计划支持的CAREER项目将扩大我们的重费米子材料的范围，超越Ce基化合物，并转向Pr基材料。 探索性合成，结构表征和磁性能测量将被用来确定影响晶体场分裂的本地化Pr 3+离子4f 2-电子配置的结构-性能关系。努力将放在单晶的合成，这将增加单晶在美国的可用性，并使明确的晶体结构和物理行为的测定。将进行非弹性中子散射研究方面的协作工作，以确定作为化学成分、压力或磁场的函数的晶体场分裂的结构效应。研究了PrAu_（2-x）Cu_xSi_2和PrAu_2Si_（2-x）格克斯以及Heusler化合物PrInT_（2-x）T？x（T，T '= Cu，Ag，Au），将是PrxTyMz（T =过渡金属，M =主族金属）探索性合成和表征的长期研究计划的基础。这项研究被整合到教育和推广活动中，涉及本科生，博士后学者和高中教师。 本科生的研究经验将通过材料化学研讨会和国家实验室的研究机会得到加强。博士后研究人员将通过参加固态化学研究和本科教育来接受全面的培训。 高中教师将在夏季研究机会期间获得固态化学的实践研究和教学经验。对量子相变的研究已经改变了我们对磁性和超导性的理解。该项目将扩大目前的量子相变材料的范围，使其面向基于Praesodynium的化合物，从而提高我们未来设计磁性和超导材料的能力。重点放在探索性的合成，结构表征和物理性能测量的单晶Praesodynium金属间化合物。在中子和同步加速器设施的晶体学实验将与磁性，热力学和电学性质的测量。单晶体的生长将解决美国可用于研究的单晶体的不足。此外，学术界和国家实验室之间的合作将扩大单晶生长能力的北方大学科罗拉多，产生更多的生产力的合成工作，并在国家实验室环境中从事学生和博士后研究人员。高中教师将在夏季研究机会期间获得固态化学的实践研究和教学经验。

TECHNICAL SUMMARY:In recent years, studies on quantum phase transitions (QPTs) in Ce-based heavy fermion compounds have transformed our understanding of magnetism and superconductivity. This CAREER project, supported by the Solid State and Materials Chemistry Program, will expand our repertoire of heavy fermion materials beyond Ce-based compounds and towards Pr-based materials. Exploratory synthesis, structural characterization, and magnetic property measurements will be used to determine structure-property relationships that impact crystal-field splitting of the localized Pr3+ ion 4f2-electronic configuration. Efforts will placed on synthesis of single-crystals, which will increase the availability of single crystals in the United States and enable unambiguous determination of crystal structure and physical behavior. Collaborative work in inelastic neutron scattering studies will be conducted to determine structural effects on crystal field splitting as a function of chemical composition, pressure or magnetic field. Investigations of PrAu2-xCuxSi2 and PrAu2Si2-x Gex and the Heusler compounds, PrInT2-xT?x (T, T'= Cu, Ag, Au), will be the foundation for a long-term research program of exploratory synthesis and characterization of PrxTyMz (T = transition metal and M = main-group metal).This research is integrated into education and outreach activities involving undergraduate students, postdoctoral scholars, and high school teachers. Undergraduate research experiences will be enhanced by materials chemistry seminars and research opportunities at national laboratories. Postdoctoral researchers will receive comprehensive training by participating in both solid-state chemistry research and undergraduate education. High school teachers will gain hands-on research and teaching experience in solid-state chemistry during summer research opportunities. NON-TECHNICAL SUMMARY:Investigations on quantum phase transitions have transformed our understanding of magnetism and superconductivity. This project will expand the current repertoire of quantum phase transition materials towards Praesodynium-based compounds, thereby enhancing our ability to design magnetic and superconducting materials in the future. Emphasis is placed on exploratory synthesis, structural characterization, and physical property measurement of single-crystals of Praesodynium-intermetallic compounds. Crystallography experiments at neutron and synchrotron facilities will be correlated with magnetic, thermodynamic and electrical property measurements. Growth of single crystals will address the deficit of single crystals available for research in the United States. In addition, collaborations between academia and national laboratories will expand single-crystal growth capabilities to University of Northern Colorado, yield more productive synthesis efforts, and engage students and postdoctoral researchers in national laboratory environments. High school teachers will gain hands-on research and teaching experience in solid-state chemistry during summer research opportunities.