Kevin Garrity

Over the past 50 years, our ability to design and fabricate materials and devices with ever-smaller components has improved to the point that many technologies are crucially dependent on surfaces and interfaces. As this process continues, the atomic details of these surfaces and interfaces will take on increasing importance, both in understanding the behavior of existing structures as well as proposing and testing new materials and devices. First principles techniques are especially well-suited for exploring these systems, as they have the predictive capability required to understand the new phenomena which emerge at atomic length scales.

In this work, we use first principles density functional theory to explore the properties of a variety of interesting surfaces and interfaces. First, we consider the thermodynamics and kinetics of Sr and La deposition on semiconductor surfaces, which is the first step in epitaxial oxide growth on semiconductors. Using this knowledge, we propose a method for growing LaAlO₃ on epitaxially on Si. In addition, we explore the surface chemistry of a ferroelectric (PbTiO₃) as a function a polarization in order to understand its applications to advanced catalysis. Finally, we investigate the coupling of phonons through an epitaxial interface between SrTiO₃ and La _1-xSr_xMnO ₃, where an interfacial coupling of atomic motion is used to dynamically modulate the conductivity of a La_1-xSr _xMnO₃ thin film