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Search Publications by: Francesca Tavazza (Fed)

Displaying 51 - 75 of 76

Facilitating the selection and creation of accurate interatomic potentials with robust tools and characterization

September 18, 2015

Author(s)

Zachary T. Trautt, Chandler A. Becker, Francesca M. Tavazza

The Materials Genome Initiative seeks to significantly decrease the cost and time of development and integration of new materials. Within the domain of atomistic simulations, several roadblocks stand in the way of reaching this goal. While the NIST

High Throughput Screening of Substrates for Synthesis and Functionalization of 2D Materials

August 26, 2015

Author(s)

Arunima Singh, Albert Davydov, Kiran Mathew, Richard G. Hennig, Francesca M. Tavazza

Several 2D materials have been synthesized experimentally, but many theoretically predicted 2D materials are yet to be synthesized. Here, we will review a density-functional theory based framework to enable high-throughput screening of suitable substrates

Sapphire as an ideal substrate and a dielectric layer for n-layer MoS2 thin films

August 5, 2015

Author(s)

Arunima Singh, Francesca M. Tavazza, Albert Davydov, Richard G. Hennig

Sapphire (α-Al2O3) is a common substrate for the growth of single- to few-layer MoS2 films, and as a high-κ dielectric gate oxide for 2D-MoS2 based transistors. Using density-functional theory calculations with a van der Waals functional we investigate the

Molecular dynamics investigation of the effects of tip-substrate interactions during nanoindentation

June 18, 2015

Author(s)

Francesca M. Tavazza, Thomas Senftle, Chenyu Zou, Chandler A. Becker, Adri van Duin

Nanoindentation in molecular dynamics simulations typically uses a much idealized indenter tip. This tip is often either a single sphere or collection of atoms, both of which are purely repulsive in their interactions with the substrate. It is also assumed

Sensitivity of gold nano conductors to voids, substitutions and electric field: ab initio results

January 16, 2015

Author(s)

Francesca M. Tavazza, Shmuel Barzilai, Lyle E. Levine

Gold nanowires are good candidates for nanoelectronics devices. A previous study has shown that the beryllium terminated BeO (0001) surface may be a useful platform for supporting nano gold conductors, since it preserves the nano-wire configuration and

Effect of wire configuration and point defects on the conductance of gold nano-conductors

February 28, 2014

Author(s)

Shmuel Barzilai, Francesca M. Tavazza, Lyle E. Levine

Gold nanowire (NW) chains are considered a good candidate for nanoelectronics devices because they exhibit remarkable structural and electrical properties. One promising nano-conductor candidate is called Hexa1. This NW configuration was found to

Considerations for choosing and using force fields and interatomic potentials in materials science and engineering

October 31, 2013

Author(s)

Chandler A. Becker, Francesca M. Tavazza, Zachary T. Trautt, Robert A. Buarque de Macedo

Atomistic simulations are increasingly important in scientific and engineering application. However, the chosen potential affects the simulation answer, sometimes significantly. Here we give some examples of this dependence and outline a set of

Disparate effects of an O2 internal impurity on the elongation and quantum transport of gold and silver nanowires

August 21, 2013

Author(s)

Shmuel Barzilai, Francesca M. Tavazza, Lyle E. Levine

In this work we investigated the effects of an internal O2 impurity on the conductance of elongated gold and silver nanowires (NWs) using density functional theory (DFT) calculations. We found that the O2 interacts with these metallic NWs very differently

Ab initio study of the mechanical and the transport properties of pure and contaminated silver nanowires

July 12, 2013

Author(s)

Shmuel Barzilai, Francesca M. Tavazza, Lyle E. Levine

The conductance and mechanical properties of pure and contaminated silver nanowires were studied using density functional theory (DFT) calculations. Several nanowires containing O2 on their surface were elongated along two different directions. All of the

Structure stability and electronic transport of gold nanowires on BeO (0001) surface

July 12, 2013

Author(s)

Shmuel Barzilai, Francesca M. Tavazza, Lyle E. Levine

Gold nanowire chains are considered a good candidate for nanoelectronics devices since they exhibit remarkable structural and electrical properties. For practical engineering devices, -wurtzite BeO may be a useful platform for supporting these nanowires

Sensitivity of gold nano conductors to common contaminations  ab initio results

May 29, 2013

Author(s)

Shmuel Barzilai, Francesca M. Tavazza, Lyle E. Levine

Gold nanowire chains are considered a good candidate for nanoelectronic devices because they exhibit remarkable structural and electrical properties. A previous study shows that the beryllium terminated BeO (0001) surface may be a useful platform for

The increase in conductance of a gold single atom chain during elastic elongation

February 7, 2013

Author(s)

Francesca Tavazza, Shmuel Barzilai, Douglas T. Smith, Lyle E. Levine

The conductance of monoatomic gold wires has been studied using ab initio calculations and the transmission was found to vary with the elastic strain. Counter-intuitively, the conductance was found to increase for the initial stages of the elongation

The effect of internal impurities on the mechanical and conductance properties of gold nanowires during elongation

January 24, 2013

Author(s)

Shmuel Barzilai, Francesca M. Tavazza, Lyle E. Levine

The conductance and mechanical properties of contaminated gold nanowires were studied using first principle calculations. Nanowires containing internal impurities of H2O or O2 were elongated along two different directions. It was found that both impurities

First-principles modeling of gold adsorption on BeO (0001)

October 29, 2012

Author(s)

Shmuel Barzilai, Francesca M. Tavazza, Lyle E. Levine

Simulation approaches for studying the conductance behavior of gold nanowires during tensile deformation.

September 30, 2011

Author(s)

Francesca M. Tavazza, Lyle E. Levine, Anne M. Chaka

Under tensile deformation, gold nanowires thin progressively through a series of metastable ordered structures down to a single atom chain. The conductance of these 1D, 2D or 3D evolving self-ordered atomic structures are examined and used as test cases to

Implications of the choice of interatomic potential on planar faults and surface properties in nickel

September 21, 2011

Author(s)

Chandler A. Becker, Francesca M. Tavazza, Lyle E. Levine

With the increasing use of molecular simulation to understand deformation mechanisms in transition metals, it is important to assess how well the simulations capture behavior both near equilibrium and under more extreme conditions. In particular, it is

Electron Transport in Gold Nanowires: Stable 1-, 2- and 3-Dimensional Atomic Structures and Non-Integer Conduction States

September 14, 2011

Author(s)

Francesca M. Tavazza, Douglas T. Smith, Lyle E. Levine, Jon R. Pratt, Anne M. Chaka

Experimental conductivity measurements made during highly stable tensile deformation of Au nanowires show a rich variety of behaviors, including non-integer quantum conductance plateaus, transitions and slopes. Using tight binding conductance calculations

Structural changes during the formation of gold single atom chains: stability criteria and electronic structure

June 17, 2010

Author(s)

Francesca M. Tavazza, Lyle E. Levine, Anne M. Chaka

Under tensile deformation, Au nanowires (NWs) elongate to form single atom chains via a series of intermediate structural transformations. These intermediate structures are investigated using semistatic density functional theory (DFT), with particular

An Ultra-Stable Platform for the Study of Single-Atom Chains

May 16, 2010

Author(s)

Douglas T. Smith, Jon R. Pratt, Francesca M. Tavazza, Lyle E. Levine, Anne M. Chaka

We describe a surface probe instrument capable of sustaining single-atomic-bond junctions in the electronic quantum-conduction regime for tens of minutes, and present results for Au junctions that can be locked stably in n = 1 and n = 2 quantum conduction

Elongation and breaking mechanisms of gold nanowires under a wide range of tensile conditions

August 27, 2009

Author(s)

Francesca Tavazza, Lyle E. Levine, Anne M. Chaka

Semistatic density functional theory is used to explore the evolution of [110] and [111] gold nanowires during tensile deformation under a wide range of conditions, including different tensile axes (along high- and low-symmetry directions), nanowire shapes

Dislocation nucleation during nanoindentation of aluminum

December 8, 2008

Author(s)

Richard J. Wagner, Li Ma, Francesca M. Tavazza, Lyle E. Levine

Through multiscale simulations, we explore the influence of an atomically-rough indenter tip on the nucleation of dislocations during nanoindentation of single-crystal aluminum. We model the long-range strain with finite element analysis using anisotropic

A Hybrid, Quantum-Classical Approach for the Computation of Dislocation Properties in Real Materials: Method, Limitations and Applications

October 16, 2008

Author(s)

Francesca Tavazza, Lyle E. Levine, Anne M. Chaka

In this work we introduce a hybrid ab initio-classical simulation methodology designed to incorporate the chemistry into the description of phenomena that, intrinsically, require very large systems to be properly described. This hybrid approach allows us

Crystal Asymmetry Induces Single-Atom Chain Formation in Gold Nanowires

October 16, 2008

Author(s)

Francesca Tavazza, A Hasmy, Lyle E. Levine, Anne M. Chaka, Luis C. Rincon, M Marquez, Carlos A. Gonzalez

We performed density functional theory and tight-binding molecular dynamics calculations to investigate the formation of suspended linear atom chains when stretching gold nanowires along the [110] crystal orientation. We determined that the chain formation

Termination Methods for Ab Initio Simulations of Metallic Clusters for Hybrid Modeling

October 16, 2008

Author(s)

Francesca Tavazza, Anne M. Chaka, Lyle E. Levine

Hybrid simulations are widely used in material science to investigate phenomena that require both a large system size and a high level of accuracy in critical regions. The most persistent difficulty lies in bridging between models that are optimized for

Electronically Induced Atom Motion in Engineered CoCu Nanostructures

August 18, 2006

Author(s)

Joseph A. Stroscio, Francesca M. Tavazza, Jason Crain, Robert Celotta, Anne M. Chaka

We have measured the quantum yield for exciting the motion of a single Co atom in CoCu n linear molecules constructed on a Cu(111) surface. The Co atom switched between two lattice positions during electron excitation from the tip of a scanning tunneling