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Christopher M. Wolverton

Publications and source records attributed to Christopher M. Wolverton.

2 recordsLinked to original sources

Predicting Interface Structure using the Minima Hopping Method with a Machine Learning Interatomic Potential

Predicting atomic-scale interfacial structures remains a central challenge in materials science due to their structural complexity and the difficulty of direct comparison between computational and experimental results. In this study, we present an efficient approach for interface structure prediction that integrates the Minima Hopping Method (MHM) with the state-of-the-art machine learning interatomic potential (MLIP), Allegro. We demonstrate that the MHM-Allegro approach provides a robust and computationally efficient route for predicting interfacial structures in the benchmark system SrTiO3 Sigma 3 (112)[110] tilt grain boundaries (GBs), consistently identifying the lowest-energy configurations across different stoichiometries. Furthermore, we introduce a strategy for constructing defect-representative training datasets without explicitly including defective configurations, achieving excellent extrapolative performance in interface predictions. The predictive capability is further validated through direct comparison with experimental observations of the SrTiO3 Sigma 5 (310)[001] GB, where the predicted atomic configurations show strong agreement with experimental measurements. This work represents a significant step toward bridging the gap between ab initio predictions and experimentally observed interfacial structures.

cond-mat.mtrl-sci

Revisiting the Influence of Sn in Cu-Al alloys: A Third Element Effect Enabling Stainless Steel Type Aqueous Passivation Behavior

The influence of Sn alloying additions on the aqueous passivation behavior of Cu-Al alloys was revisited and found to function as a new third element effect in acidified 0.1 M Na2SO4 solution. The role of each element during the process of aqueous passivation was investigated using electrochemical and surface-sensitive ex-situ and in-operando spectroscopic techniques. The connection between passivation and the atomic arrangements of atoms in the solid solution was supported by first principles based cluster expansion calculations and Monte Carlo simulations probing the chemical short-range order in the Cu-Al-Sn system. High purity Sn, like high purity Cu, did not passivate in the test environment, whereas high purity Al formed a passive film with a stable passive current density of 0.01 mA/cm^2. Cu-xAl-Sn solid solution alloys where x greater than 18 at.%, containing less than 3 at.% Sn additions exhibited lower corrosion rates than Cu-xAl alloys, brought by Al(III) and Sn(IV, II) unidentified complex oxides formation on the surface. A strong influence of Sn on Al(III) passivation was observed, i.e., strongly suggesting a third element effect type behavior. Possible governing processes explaining the stainless steel type corrosion behavior are discussed, providing insights for exploring novel synergies in the design of corrosion resistant alloys.

cond-mat.mtrl-sci