Using high-pressure conditions to access novel structures and engender magnetic control in lanthanide materials

A rational approach to designing the next generation of quantum materials requires hypothesis-driven synthesis. Yet, the complex phase space of solid-state systems and the small energy scales that determine electronic and magnetic order are such that subtle changes in composition can drastically change the structure and properties of the resulting material. In comparison, pressure provides an incrementally tunable vector, serving to increase orbital overlap and leading to more significant covalent interactions and charge delocalization. Thus, the application of static pressure opens up vast regions of phase-space for synthesizing new solid-state materials. However, often times the same attributes that challenge our understanding also lead them to not be recoverable to ambient conditions. It is therefore vital to characterize the structure and properties of these materials in situ in order to gain insight into how these new structural motifs influence the behavior of the materials. In this work, we describe our multimodal approach combining high-pressure synthesis with spectroscopy and calculations to bring new chemical insight into the discovery of materials containing lanthanides primed to exhibit exotic magnetic behaviors. To realize promising synthetic targets, we turned to both traditional solid-state techniques as well as high-pressure experiments in diamond anvil cells. We will discuss our burgeoning chemical intuition for structure formation and metastability in lanthanide intermetallic phase space, as well as present our ongoing efforts towards correlating new structures with magnetic properties both at ambient pressures and under high-pressure synthesis conditions.