@article{irving_padgett_guo_mintmire_brenner_2009, title={Multiscale Modeling of Metal-Metal Contact Dynamics Under High Electromagnetic Stress: Timescales and Mechanisms for Joule Melting of Al-Cu Asperities}, volume={45}, ISSN={["0018-9464"]}, DOI={10.1109/tmag.2008.2008544}, abstractNote={An analysis and initial results from a multiscale continuum-atomistic simulation of the Joule heating and melting of Cu-Al asperity contacts is presented. An analytic expression is given for the time needed to reach the Al melting point for an asperity as a function of the voltage drop and the asperity contact area. The coupled continuum-atomistic simulations capture the initial stages of the formation of Al-Cu alloys that arises from the solvation of Cu atoms into the Al melt. Implications of these results for understanding contacts in electromagnetic launchers are discussed.}, number={1}, journal={IEEE TRANSACTIONS ON MAGNETICS}, author={Irving, Douglas L. and Padgett, Clifford W. and Guo, Yin and Mintmire, John W. and Brenner, Donald W.}, year={2009}, month={Jan}, pages={331–335} }
 @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} }
 @misc{hu_shenderova_hu_padgett_brenner_2006, title={Carbon nanostructures for advanced composites}, volume={69}, ISSN={["1361-6633"]}, DOI={10.1088/0034-4885/69/6/R05}, abstractNote={Recent advances in the science and technology of composites utilizing carbon nanostructures are reviewed, including experimental results and modelling studies of composite properties and processing. Carbon nanotubes are emphasized, with other carbon nanostructures such as fullerenes, ultradispersed diamond clusters and diamond nanorods also being discussed.}, number={6}, journal={REPORTS ON PROGRESS IN PHYSICS}, author={Hu, Yanhong and Shenderova, Olga A. and Hu, Zushou and Padgett, Clifford W. and Brenner, Donald W.}, year={2006}, month={Jun}, pages={1847–1895} }
 @article{abdelmaksoud_lee_padgett_irving_brenner_krim_2006, title={STM, QCM, and the windshield wiper effect: A joint theoretical-experimental study of adsorbate mobility and lubrication at high sliding rates}, volume={22}, ISSN={["0743-7463"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-34247572834&partnerID=MN8TOARS}, DOI={10.1021/la061797w}, abstractNote={We have observed that when mobile adsorbed films of benzene, tricresyl phosphate, and tertiary-butyl phenyl phosphate are present on the surface electrode of a quartz crystal microbalance (QCM), oscillation of the QCM produces clearer scanning tunneling microscope (STM) images of the electrode surface. This is in contrast to an immobile overlayer of iodobenzene, where oscillation of the QCM does not affect image quality. This observation is attributed to a "windshield wiper effect", where at MHz frequencies the tip motion maintains a region of the surface where the absorbate concentration is reduced, which leads to a clearer image. A straightforward model is presented that supports this conclusion and that provides guidelines for effective lubrication of contacts operating at MHz frequencies.}, number={23}, journal={LANGMUIR}, author={Abdelmaksoud, M. and Lee, S. M. and Padgett, C. W. and Irving, D. L. and Brenner, D. W. and Krim, J.}, year={2006}, month={Nov}, pages={9606–9609} }
 @article{padgett_shenderova_brenner_2006, title={Thermal conductivity of diamond nanorods: Molecular simulation and scaling relations}, volume={6}, ISSN={["1530-6992"]}, DOI={10.1021/nl060588t}, abstractNote={Thermal conductivities of diamond nanorods are estimated from molecular simulations as a function of radius, length, and degree of surface functionalization. While thermal conductivity is predicted to be lower than carbon nanotubes, their thermal properties are less influenced by surface functionalization, making them prime candidates for thermal management where heat transfer is facilitated by cross-links. A scaling relation based on phonon surface scattering is developed that reproduces the simulation results and experimental measurements on silicon nanowires.}, number={8}, journal={NANO LETTERS}, author={Padgett, Clifford W. and Shenderova, Olga and Brenner, Donald W.}, year={2006}, month={Aug}, pages={1827–1831} }
 @article{padgett_brenner_2005, title={A continuum-atomistic method for incorporating Joule heating into classical molecular dynamics simulations}, volume={31}, ISSN={["1029-0435"]}, DOI={10.1080/08927020500262614}, abstractNote={A hybrid atomistic-continuum method is presented for incorporating Joule heating into large-scale molecular dynamics (MD) simulations. When coupled to a continuum thermostat, the method allows resistive heating and heat transport in metals to be modeled without explicitly including electronic degrees of freedom. Atomic kinetic energies in a MD simulation are coupled via an ad hoc feedback loop to continuum current and heat transfer equations that are solved numerically on a finite difference grid (FDG). For resistive heating, the resistance in each region of the FDG is calculated from the experimental resistivity, atomic density, and average kinetic energy in the MD simulation. A network of resistors is established from which the potential at every FDG region is calculated given an applied voltage. The potential differences and the resistance between connected FDG regions are used to calculate the current between the two points and the heat generated from that current. This information is then added back into the atomic simulation. The method is demonstrated by simulating Joule heating and melting, along with associated changes in current, of single and bundles of metal nanowires, as well as a “pinched” wire under applied strain.}, number={11}, journal={MOLECULAR SIMULATION}, author={Padgett, CW and Brenner, DW}, year={2005}, month={Sep}, pages={749–757} }
 @article{schall_padgett_brenner_2005, title={Ad hoc continuum-atomistic thermostat for modeling heat flow in molecular dynamics simulations}, volume={31}, ISSN={["1029-0435"]}, DOI={10.1080/08927020512331336898}, abstractNote={An ad hoc thermostating procedure that couples a molecular dynamics (MD) simulation and a numerical solution to the continuum heat flow equation is presented. The method allows experimental thermal transport properties to be modeled without explicitly including electronic degrees of freedom in a MD simulation. The method is demonstrated using two examples, heat flow from a constant temperature silver surface into a single crystal bulk, and a tip sliding along a silver surface. For the former it is shown that frictional forces based on the Hoover thermostat applied locally to grid regions of the simulation are needed for effective feedback between the atomistic and continuum equations. For fast tip sliding the thermostat results in less surface heating, and higher frictional and normal forces compared to the same simulation without the thermostat.}, number={4}, journal={MOLECULAR SIMULATION}, author={Schall, JD and Padgett, CW and Brenner, DW}, year={2005}, month={Apr}, pages={283–288} }
 @article{shenderova_padgett_hu_brenner_2005, title={Diamond nanorods}, volume={23}, ISSN={["2166-2746"]}, DOI={10.1116/1.2122907}, abstractNote={Diamond nanorods are one-dimensional carbon nanostructures consisting of all sp3 bonded carbon atoms. They represent an alternative class of carbon structure to fullerene nanotubes for potential applications in nanocomposites for mechanical reinforcement and thermal management, as well as in microelectronics. Synthetic routes for creating diamond nanorods (and related structures) and recent predictions of their stability, mechanical, and thermal properties are summarized in the article.}, number={6}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B}, author={Shenderova, OA and Padgett, CW and Hu, Z and Brenner, DW}, year={2005}, pages={2457–2464} }
 @article{padgett_brenner_2004, title={Influence of chemisorption on the thermal conductivity of single-wall carbon nanotubes}, volume={4}, ISSN={["1530-6992"]}, DOI={10.1021/nl049645d}, abstractNote={The thermal conductivity at 300 K of (10,10) carbon nanotubes that have been functionalized by chemical attachment of phenyl rings through covalent bonding (chemisorption) at random positions has been calculated as a function of adsorption density using classical trajectories. The system exhibits a rapid drop in thermal conductivity with chemisorption, where chemisorption to as little as 1.0% of the nanotube carbon atoms reduces the thermal conductivity by over a factor of 3. The simulation results indicate that the effect is due to a reduction in phonon scattering length rather than changes in the vibrational frequencies of the carbon atoms in the nanotube.}, number={6}, journal={NANO LETTERS}, author={Padgett, CW and Brenner, DW}, year={2004}, month={Jun}, pages={1051–1053} }