DMREF: Integrated Computational Framework for Designing Dynamically Controlled Alloy-Oxide Heterostructures

University Of California-Santa Barbara, Santa Barbara CA

Investigators

Abstract

Non-technical Description: Many technologies rely on heterostructures made of materials with very different chemistries. Examples include (i) turbine blades in jet engines, (ii) microelectronic applications that rely on semiconductor-oxide heterostructures and (iii) electrochemical energy storage devices such as all solid-state batteries. Heterostructures are often out of equilibrium due to the close proximity of very different chemistries. This results in the evolution of the heterostructure with a concomitant degradation of its functional capabilities over time. Predicting the evolution of heterostructures consisting of widely differing chemistries remains one of the biggest challenges in materials science and requires a description of processes that span widely varying length and time scales. The processes that dominate heterostructure evolution are common to most other non-equilibrium processes in the solid state. This project will lead to the development of an openly distributable framework that rigorously integrates theory, experiment and computation to predict and elucidate the evolution of complex materials heterostructures. It will address an important challenge within the Materials Genome Initiative of linking the electronic structure of the constituent chemistries of a complex materials system to its behavior at technologically relevant length and time scales. Technical Description: The aim of this project is to develop a rigorous framework and accompanying predictive infrastructure that integrates multi-scale computation with precise experimental characterization to predict and elucidate the evolution of complex heterostructures and multi-phase coexistence. A specific focus will target the measurement and prediction of thermodynamic and kinetic properties of individual and combined oxidation processes in selected model alloys. The methods to be developed and integrated will be more generally applicable to evolving multi-phase coexistence between metallic, semiconducting and insulating phases, where evolution requires atomic diffusion, electron transport, phase nucleation and growth coupled with interface migration. The activity will focus on model systems presenting a clear case for benchmarking and validating multiscale models that bridge descriptions of atomistic processes with continuum length scales. A major objective is to define design criteria for the stability and evolution of oxide/metal structures. Experimental measurements will be tightly integrated with modeling tasks, providing both input and validation. While the emphasis is on oxidation in model systems that exhibit a range of dynamic phenomena involving interfaces between different phases, the tools and integrated research methodology will be applicable to any dynamically evolving heterostructure system coupling phase evolution with atomic and electronic transport. This includes batteries, fuel cells, and corrosion processes.