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

技术摘要：近年来，铈基重费米子化合物的量子相变（QPTs）研究改变了我们对磁性和超导性的认识。这个CAREER项目由固态和材料化学项目支持，将扩大我们的重费米子材料的范围，超越ce基化合物，向pr基材料发展。探索性合成、结构表征和磁性测量将用于确定影响局域Pr3+离子4f2电子构型晶体场分裂的结构-性质关系。将致力于单晶的合成，这将增加美国单晶的可用性，并使晶体结构和物理行为的明确测定成为可能。将进行非弹性中子散射研究的合作工作，以确定化学成分、压力或磁场对晶体场分裂的结构影响。PrAu2-xCuxSi2和PrAu2Si2-x Gex及Heusler化合物PrInT2-xT？x （T, T′= Cu, Ag, Au）将为探索性合成和表征PrxTyMz （T =过渡金属，M =主族金属）的长期研究计划奠定基础。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。博士后研究人员将接受固态化学研究和本科教育相结合的综合培训。高中教师将在暑期研究期间获得固态化学的实践研究和教学经验。非技术总结：对量子相变的研究改变了我们对磁性和超导性的理解。该项目将把现有的量子相变材料扩展到基于准钕的化合物，从而增强我们未来设计磁性和超导材料的能力。重点是探索性合成、结构表征和单晶金属间化合物的物理性质测量。中子和同步加速器设施的晶体学实验将与磁性、热力学和电学性质测量相关联。单晶的生长将解决美国可用于研究的单晶短缺问题。此外，学术界和国家实验室之间的合作将扩大北科罗拉多大学的单晶生长能力，产生更有成效的合成努力，并吸引学生和博士后研究人员参与国家实验室环境。高中教师将在暑期研究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.