Seminars

Phase transformation materials are characterized by their ability to rapidly and reversibly switch between distinct properties, such as insulating and conducting, paramagnetic and ferromagnetic, or Li-rich and Li-poor. These transformations commonly trace out a characteristic hysteresis curve as a function of the applied field, such as voltage hysteresis in electrodes and magnetic hysteresis loops in soft magnets.  In our work, we develop models to investigate the origins of hysteresis in multifunctional materials from the viewpoint of energy barriers and Ericksen’s multiple energy wells. By doing so, we identify important links between material constants, crystallographic microstructures, and macroscopic properties. This approach to understanding material behavior from the perspective of energy landscapes may suggest new ways to design materials with improved reversibility and lifespan. In this talk, I will present our findings on phase transformations in battery electrodes (intercalation compounds), soft magnets, and photomechanical materials (molecular crystals).