@article{purohit_sun_shenderova_scattergood_brenner_2011, title={First-principles-based mesoscale modeling of the solute-induced stabilization of < 1 0 0 > tilt grain boundaries in an Al-Pb alloy}, volume={59}, ISSN={["1873-2453"]}, DOI={10.1016/j.actamat.2011.07.056}, abstractNote={A first-principles disclination structural units (DSUM) model was used to calculate the energies of 12 〈0 0 1〉 symmetric tilt grain boundaries in Al for a pure system and a system in which Pb atoms substitute for Al at one-half of the lattices sites along the interfacial plane. The grain boundaries are modeled as disclination dipole walls with energies given as a weighted sum of individual disclination energies determined from special low-sigma structures, elastic terms and disclination core energies. Predictions of the DSUM using the bulk Al shear modulus and Poisson’s ratio in the elastic and core energy terms are found to be comparable to energies for fully atomistic simulations calculated using a modified embedded-atom method (MEAM) potential. No relation between grain boundary energies in pure Al and the degree of stabilization due to Pb doping was found. The DSUM parameterized to density functional theory calculations predicts a ∼50% reduction in the energy anisotropy with respect to angle due to doping compared to the pure system, while MEAM calculations yield no appreciable reduction in the energy anisotropy.}, number={18}, journal={ACTA MATERIALIA}, author={Purohit, Y. and Sun, L. and Shenderova, O. and Scattergood, R. O. and Brenner, D. W.}, year={2011}, month={Oct}, pages={7022–7028} }
 @article{purohit_sun_irving_scattergood_brenner_2010, title={Computational study of the impurity induced reduction of grain boundary energies in nano- and bi-crystalline Al-Pb alloys}, volume={527}, ISSN={["0921-5093"]}, DOI={10.1016/j.msea.2009.11.034}, abstractNote={Abstract Segregation of impurities with limited solubilities to grain boundaries can slow or even eliminate grain growth in nanocrystalline materials. Due to a very limited miscibility Pb is a potential candidate for thermodynamically stabilizing nanocrystalline Al. To investigate this we have used atomic modeling to characterize the structure and energy of substitutional Pb defects in bulk Al, in Al bi-crystals and in an Al nanocrystal. Monte Carlo simulations using a modified embedded-atom method (MEAM) potential fit to the results of density functional theory (DFT) calculations predict the formation of Pb clusters, in agreement with prior experiments. In addition, the simulations show strong segregation of Pb atoms to grain boundaries, a result that supports prior suggestions that Pb is distributed along grain boundaries in nanocrystals created by ball milling. Analysis of the enthalpies for Pb defects using MEAM and DFT calculations suggests that Pb impurities can help stabilize nanocrystalline Al against grain growth.}, number={7-8}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Purohit, Y. and Sun, L. and Irving, D. L. and Scattergood, R. O. and Brenner, D. W.}, year={2010}, month={Mar}, pages={1769–1775} }
 @article{purohit_jang_irving_padgett_scattergood_brenner_2008, title={Atomistic modeling of the segregation of lead impurities to a grain boundary in an aluminum bicrystalline solid}, volume={493}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2007.05.128}, abstractNote={Using Monte Carlo simulations, new insights into the atomic segregation of lead (Pb) impurities to a Σ5 〈1 0 0〉 {2 1 0} tilt aluminum (Al) grain boundary have been obtained. Interatomic interactions in the Al–Pb alloy system were described using a modified embedded atom method potential with parameters that fit to the results of density functional calculations. The simulations predict segregation of Pb impurities along the Al grain boundary prior to the formation of Pb clusters. Analyses of grain boundary energies for varying concentrations of Pb suggests that grain boundaries in Al can be thermodynamically stabilized by Pb impurities with respect to a dilute solid solution of Pb in Al.}, number={1-2}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Purohit, Y. and Jang, S. and Irving, D. L. and Padgett, C. W. and Scattergood, R. O. and Brenner, D. W.}, year={2008}, month={Oct}, pages={97–100} }
 @article{jang_purohit_irving_padgett_brenner_scattergood_2008, title={Influence of Pb segregation on the deformation of nanocrystalline Al: Insights from molecular simulations}, volume={56}, ISSN={["1359-6454"]}, DOI={10.1016/j.actamat.2008.05.024}, abstractNote={Molecular dynamics straining simulations using a two-dimensional columnar model were run for pure Al with grain sizes from 5 to 30 nm, and for 10 nm grain size Al–Pb alloys containing 1, 2 and 3 at.% Pb. Monte Carlo simulations showed that all the Pb atoms segregate to the grain boundaries. Pb segregation suppresses the nucleation of partial dislocations and twins during straining. At 3 at.% Pb, no dislocations or twins are observed throughout the straining history. It also appeared that Pb tends to segregate to the same locations in grain boundaries that were favorable for partial dislocation emission. Grain boundaries with Pb segregates were very robust against dissociation during straining compared to pure Al. The yield stress determined from stress–strain curves showed a decrease with increasing Pb content, supporting a similar observation for the hardness change measured on nanocrystalline Al–Pb alloys.}, number={17}, journal={ACTA MATERIALIA}, author={Jang, S. and Purohit, Y. and Irving, D. L. and Padgett, C. and Brenner, D. and Scattergood, R. O.}, year={2008}, month={Oct}, pages={4750–4761} }
 @article{jang_purohit_irving_padgett_brenner_scattergood_2008, title={Molecular dynamics simulations of deformation in nanocrystalline Al-Pb alloys}, volume={493}, ISSN={["0921-5093"]}, DOI={10.1016/j.msea.2007.05.130}, abstractNote={Abstract A modified embedded-atom method (MEAM) potential was developed and used for molecular dynamics (MD) straining simulations of Al–Pb alloys with a grain size of 10 nm and Pb content up to 3 at.%. Monte Carlo (MC) simulations done at 300 K indicated that all the Pb is segregated to the grain boundaries in these alloys. As the Pb content increases, partial dislocation nucleation at grain boundaries is suppressed, and the plastic strain is accommodated by mechanisms other than dislocation slip. The increasing Pb content was accompanied by a reduction in the yield and peak stress values.}, number={1-2}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Jang, S. and Purohit, Y. and Irving, D. and Padgett, C. and Brenner, D. and Scattergood, R. O.}, year={2008}, month={Oct}, pages={53–57} }
 @article{purohit_irving_scattergood_brenner_2008, title={Prediction of Energies of <100> Tilt Boundaries in Al-Pb Alloy}, volume={1056E}, journal={Materials Research Society Symposium Proceedings}, author={Purohit, Y. and Irving, D. L. and Scattergood, R. O. and Brenner, D. W.}, year={2008}, pages={1056–HH01-105610} }