Strongly Correlated Electron Behavior in Intermetallics with an Emphasis on Novel Borides, Carbides, and Noncentrosymmetric Systems

Louisiana State University, Baton Rouge LA

Investigators

Abstract

****NON-TECHNICAL ABSTRACT**** This individual investigator award supports research focusing on the synthesis of materials that possess very unique physical properties resulting from strong correlations between the electrons in the material. One of these properties is superconductivity. When a material becomes a superconductor, it loses all of its resistance to the flow of electricity. How the electrons in a material actually accomplish this amazing feat has been the goal of much experimental and theoretical research. It is now known that the superconducting state depends on many factors, one of which is the material's structure. One goal of this project is to elucidate how superconductivity is related to the structure of novel materials, many of which contain carbon or boron. These elements often form large structural units in their compounds. This increased structural complexity allows a greater range of optimization in the superconducting properties. Another goal of the project is to investigate the improvement and discovery of new materials that can be utilized for applications in the emerging field of spintronics (spin-based electronics), which exploits not only the charge on the electron, but also its intrinsic magnetic properties; "spin" and "magnetic moment." Finding a better material for spintronics applications could revolutionize the computer memory industry. The results obtained from the experimental studies enabled by this award will be compared to the relevant theories and will aid in our understanding of strongly correlated electron systems in general. This research could lead to the discovery of new materials that display exotic magnetic or electronic properties. The research will be integrated into an educational plan, which over a 3-year period is intended to enhance both graduate and undergraduate learning in the laboratory and classroom. This experimental research will provide post-doctoral associates, graduate, and undergraduate students with valuable experience in the areas of materials synthesis, structural characterization, measurement of physical properties as a function of temperature and magnetic field, and data acquisition and analysis. ****TECHNICAL ABSTRACT**** This individual investigator award supports an experimental investigation of the electronic and magnetic ground states in novel intermetallic systems. The focus of the project will be on intermetallic borides, carbides, and noncentrosymmetric systems. These strongly correlated electron materials depend sensitively on parameters such as sample stoichiometry, carrier density, temperature, chemical/physical pressure, and magnetic field. Intermetallic systems exhibit a wide range of ground states ranging from superconductors to Kondo insulators to high temperature ferromagnetism. Synthesizing and investigating new noncentrosymmetric superconductors, such as Mo(3)Al(2)C, with unconventional pairing symmetries will enable theoretical work to be compared to experimental results. Chemical doping of Kondo insulators, for example FeSi, into higher-temperature ferromagnets and control over the high-temperature ferromagnetism in the alkaline earth hexaborides could lead to important technological applications in the emerging field of spintronics. The experimental results enabled by this award will aid in our understanding of strongly correlated electron systems in general. This research could lead to the discovery of new materials that display exotic magnetic or electronic properties. The research will be integrated into an educational plan that over a 3-year period is intended to enhance both graduate and undergraduate learning in the laboratory and classroom. This experimental project will provide post-doctoral associates, graduate, and undergraduate students with valuable experience in the areas of materials synthesis, structural characterization, measurement of physical properties as a function of temperature and magnetic field, and data acquisition and analysis.