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

技术综述：近年来，对Ce基重费米子化合物中量子相变的研究改变了我们对磁性和超导电性的理解。这个职业项目由固态和材料化学计划支持，将把我们的重费米子材料的范围从Ce基化合物扩展到Pr基材料。探索性合成、结构表征和磁性测量将被用于确定影响局域Pr3+离子4F2-电子组态的晶场分裂的结构-性质关系。将致力于单晶的合成，这将增加单晶在美国的可获得性，并能够明确地确定晶体结构和物理行为。将开展非弹性中子散射研究方面的合作工作，以确定作为化学成分、压力或磁场的函数对晶场分裂的结构影响。PrAu2-xCuxSi2和PrAu2Si2-x Gex和Heusler化合物PrInT2-xT？x(T，T‘=Cu，Ag，Au)的研究将成为PrxTyMz(T=过渡金属和M=主族金属)探索性合成和表征的长期研究计划的基础。这项研究被整合到本科生、博士后学者和高中教师的教育和推广活动中。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接受全面培训。高中教师将在暑期研究机会中获得固态化学的实践研究和教学经验。非技术综述：对量子相变的研究改变了我们对磁性和超导的理解。该项目将把目前的量子相变材料库扩展到基于稀土元素的化合物，从而提高我们未来设计磁性和超导材料的能力。重点介绍了稀土金属间化合物单晶的探索性合成、结构表征和物理性能测试。在中子和同步加速器设施中的结晶学实验将与磁学、热力学和电学性质测量相关联。单晶的生长将解决美国可供研究的单晶短缺的问题。此外，学术界和国家实验室之间的合作将把单晶生长能力扩展到北科罗拉多大学，产生更多富有成效的合成努力，并在国家实验室环境中吸引学生和博士后研究人员。高中教师将在暑期研究机会中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.