Directed Rational Synthesis of Kagome Lattices for the Discovery of Emergent Materials 9.3 Physical Properties of Materials

1. Scientific Objectives Spin liquids are emergent phases of matter that arise from strongly correlated electrons in a crystalline solid. In a spin liquid, analogous to ordinary liquids, there are a nearly infinite number of degenerate states for the spins with no clear single ground state. Currently, the scant number of chemically pure, structurally perfect spin liquid candidates inherently constrains the field. Herein we propose the application of inorganic synthetic chemistry to the challenge of the synthesis of spin liquids. This research will build upon our previous work both in the geologically inspired synthesis of magnetic materials, and the synthesis of frustrated materials. Goals: (1) Create new spin liquids using three well-known models of magnetic frustration via a hybrid organic-inorganic approach, (2) Incorporate orbital angular momentum into magnetically frustrated lattices types to engender theorized exotic phases such as topological magnon insulators (3) Study the magnetic and physical properties of these systems and search for new physical phenomena. 2. Methods to be employed We propose a pathway to the design, discovery, and characterization emergent materials exhibiting classical or quantum spin liquid ground states, where competing interactions lead to fractional particle excitations. Utilizing solid-state synthesis to design specific magnetic interactions within a given lattice type is a challenge, in particular for phases like oxide materials. We will employ geologically inspired synthetic approaches to enable the creation of a new class of exotic compounds. Creating new materials will be supported by the synthesis of new molecular building blocks for reactions. By harnessing molecular and soft-chemical synthetic approaches we will synthesize and investigate new materials. The Freedman Laboratory’s expertise synthesizing and characterizing magnetic compounds will be brought to bear on the challenge of synthesizing new materials, and understanding their magnetic properties. Standard solution phase anaerobic synthetic techniques will be employed to synthesize building units for new materials. This building block approach will be used to both create hybrid metal-organic materials and oxide based compounds. These molecules will be characterized by single crystal X-ray diffraction and measured by magnetometry techniques. Ac susceptibility will be used to probe for spin glass vs. spin liquid behavior. Observed spin behavior will be traced back to structural and electronic features of the materials and used to direct future compound design. 3. Significance of Project Emergent materials, in which new and exciting properties arise from collective behavior, lie at the frontier of our conception of the physical universe. One fundamental and captivating property of emergent materials is the potential for the discovery of novel quasiparticles within these compounds, a phenomenon that points to the recent unconventional, but compelling, suggestion that these materials could be new phases of matter. Beyond displaying scientifically intriguing properties, our target compounds may have transformative future impact across society, with potential applications in power transmission, quantum computation, and medical imaging. For example, two-dimensional magnetically frustrated lattices are proposed to have spin liquid ground states, emergent phases of matter with correlated electrons. Such systems may shed insight into the pairing mechanism for high-Tc superconductivity and serve as a materials platform for quantum