Dr. Nancy Ross

Abstract:

Framework structures, which feature three-dimensional networks of relatively rigid polyhedral units that share corners with one another, encompass a wide range of natural and synthetic compounds of importance in Earth science, chemistry, physics, and materials science. Examples include feldspars, zeolites, garnets, perovskites and hybrid materials such as metal-organic frameworks (MOFs). The inherent flexibility of the framework gives rise to many interesting phenomena that control the stabilities of the materials.  These phenomena include extensive polymorphism, negative volumes of fusion, very low to negative thermal expansion, a P-T region of pressure induced amorphization, and polyamorphism. These properties serve as inspirations that form the basis of many technological materials such as photovoltaics, sensors, catalysts, lasers, molecular sieves, etc. The Ross group studies the structure-property relations of framework materials using a combination of methods including X-ray diffraction, Raman spectroscopy and inelastic neutron spectroscopy to explore how the flexible structural framework is related to their thermodynamic, elastic and physical properties[1-5]. This talk will present an overview of how structural changes influence mechanical functionality and ongoing ultimately lead to the development of novel materials based on this important group of materials.