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Full-Text Articles in Engineering
Atomistic Simulations Of Novel Nanoscale Semiconductor Devices: Resistance Switches And Two-Dimensional Transistors, Joseph P. Anderson, Mahbubul Islam, David Guzman, Alejandro Strachan
Atomistic Simulations Of Novel Nanoscale Semiconductor Devices: Resistance Switches And Two-Dimensional Transistors, Joseph P. Anderson, Mahbubul Islam, David Guzman, Alejandro Strachan
The Summer Undergraduate Research Fellowship (SURF) Symposium
As transistors get smaller, we are achieving record levels of memory density. However, there is a limit to how small transistors can be made before their functionality breaks down. Thus alternatives to traditional transistor technology are needed. The two such technologies we examined are: resistance switching devices, which reversibly grow metal filaments through a dielectric, and two-dimensional transistors, which are capable of breaking through the scalability limit of traditional transistors. In order to design resistance switching devices which create filaments with some level of consistency, the dynamics of the filament formation need to be explored. Herein we model this process …
Modal Phonon Transport Across Interfaces By Non-Equilibrium Molecular Dynamics Simulation, Yang Zhong, Tianli Feng, Xiulin Ruan
Modal Phonon Transport Across Interfaces By Non-Equilibrium Molecular Dynamics Simulation, Yang Zhong, Tianli Feng, Xiulin Ruan
The Summer Undergraduate Research Fellowship (SURF) Symposium
Phonons represent the quantization of lattice vibration, responsible for heat transfer in semiconductors and dielectrics. Phonon heat conduction across interfaces is crucially important for the thermal management of real-life devices such as smartphones, electric vehicles, and satellites. Although recent studies have broadly investigated spectral phonon contribution to lattice thermal conductivity, the mechanism of phonon modal transport across interfaces is still not well-understood. Previous models, including the acoustic mismatch model (AMM) and diffuse mismatch model (DMM), only consider elastic process while neglecting inelastic phonon contributions. Herein, we employ spectral Non-Equilibrium Molecular Dynamics Simulation (NEMD) to probe the temperature and heat flux …
Dislocation Engineering In Novel Nanowire Structures, Christopher Y. Chow, Samuel T. Reeve, Alejandro Strachan
Dislocation Engineering In Novel Nanowire Structures, Christopher Y. Chow, Samuel T. Reeve, Alejandro Strachan
The Summer Undergraduate Research Fellowship (SURF) Symposium
Leveraging defects is a cornerstone of materials science, and has become increasingly important from bulk to nanostructured materials. We use molecular dynamics simulations to explore the limits of defect engineering by harnessing individual dislocations in nanoscale metallic specimens and utilizing their intrinsic behavior for application in mechanical dampening. We study arrow-shaped, single crystal copper nanowires designed to trap and control the dynamics of dislocations under uniaxial loading. We characterize how nanowire cross-section and stacking-fault energy of the material affects the ability to trap partial or full dislocations. Cyclic loading simulations show that the periodic motion of the dislocations leads to …
Relative Contributions Of Inelastic Phonon Scattering And Elastic Phonon Scattering To Thermal Boundary Conductance Across Solid Interfaces, Mengxi Zhao, Zexi Lu, Xiulin Ruan
Relative Contributions Of Inelastic Phonon Scattering And Elastic Phonon Scattering To Thermal Boundary Conductance Across Solid Interfaces, Mengxi Zhao, Zexi Lu, Xiulin Ruan
The Summer Undergraduate Research Fellowship (SURF) Symposium
The knowledge of inelastic phonon scattering is crucial for the understanding of thermal boundary conductance across solid interfaces. Several traditional theoretical models such as the acoustic mismatch model (AMM) and the diffuse mismatch model (DMM) assume that the elastic phonon scattering drives the thermal transport across the interface. But there are experiments indicating that the inelastic phonon scattering plays an important part in the interfacial thermal energy conduction as well. We use nonequilibrium molecular dynamics (NEMD) to predict the inelastic phonon conductance across Cu/Si interface. Temperature distribution across Cu/Si interface has been obtained from the simulation results, and a temperature …
Molexpl: A Tool For Ab Initio Data Exploration And Visualization, Xueying Wang, Nicolas Onofrio, Alejandro Strachan
Molexpl: A Tool For Ab Initio Data Exploration And Visualization, Xueying Wang, Nicolas Onofrio, Alejandro Strachan
The Summer Undergraduate Research Fellowship (SURF) Symposium
Density functional theory (DFT) based on ab initio theory, is a powerful method to resolve the electronic structure of atoms, molecules and solids. However, in practical, DFT is limited to few hundreds of atoms. To overcome this limitation, researchers have developed empirical interatomic potentials implemented in molecular dynamics (MD) simulations. MD ignores the movements of electrons and describes bonding and non-bonding interaction as a function of the distance between atoms called force fields (FF) or interatomic potentials. These empirical potentials are optimized against large datasets of DFT calculations relevant to describe the interactions between the atoms included in the training …
Designing Meaningful Molecular Dynamics (Md) Simulations: The Lithiation Of Silicon, María Camila Rincon, Alejandro Strachan, Hojin Kim, David Guzman, Mathew Cherukara
Designing Meaningful Molecular Dynamics (Md) Simulations: The Lithiation Of Silicon, María Camila Rincon, Alejandro Strachan, Hojin Kim, David Guzman, Mathew Cherukara
The Summer Undergraduate Research Fellowship (SURF) Symposium
Molecular dynamics (MD) is used to understand the properties of materials by following the time evolution of the system and exploring the interactions between its constituent atoms. MD simulation allows making reliable predictions of various properties of materials; however, designing useful computer experiments is a complex task that requires the appropriate selection of interatomic interactions (force fields) and other conditions. In this work we discuss some aspects of molecular dynamics that would help the inexperienced users design reliable simulations. The simulation of the lithiation process of silicon is taken as an example for better understanding.