Navigating the Energy Landscape of Martensitic Transformations

Abstract

The following work presented focuses on the characterization and navigation of energy landscapes in systems that undergo solid state phase transformations; including the broad category of shape memory alloys, with extended study of the model systems copper zirconium (CuZr-X), doped vanadium dioxide (VO2B) and carbon nitride (C4N3). The third section on CuZr-X and HTSMA Database will present computational results used to guide selection of alloying elements (Ni ,Co, Hf) for manipulating the transition temperature (Tc) and lattice compatibility of CuZrX, a high temperature shape memory alloy (HTSMA). In the same section, a broader outlook on the systematic discovery of HTSMAs is given through the generation of a binary alloy database with practical formulation to predict the effects of alloying elements on hysteresis. A similarity metric based on the fretchet distance between minimum energy pathways is introduced as a tool for catergorizing and eliminating subsets of related systems. Section 4 details an algorithm for systematic doping of group-subgroup related phases developed to resolve the energy landscape of boron metastable conditions in VO2 induced by a phase transformation. Section 5 will introduce the development of a general metric based solely on structural features and its practical application in the study of dynamical stability in carbon-nitride systems.