First principles modeling of materials: from electrochemical metallization cells and the design of ultra-low stiffness metals to open cloud computing in nanoHUB

Seminar by Alejandro Strachan,

Professor of Materials Engineering at Purdue University

Deputy Director of the Purdue’s Center for Predictive Materials and Devices (c-PRIMED)

 

First principles-based modeling is playing an increasingly important role in the design of new materials and understand of novel devices for a range of applications. I will discuss new methods and applications of atomistic simulations applied to technologically important problems:

Nanoscale resistance-switching cells that operate via the electrochemical formation and disruption of metallic filaments that bridge two electrodes are among the most promising devices for post-CMOS electronics. I will discuss the first atomistic simulations of their operation using reactive molecular dynamics simulations enhanced to model electrochemistry. The simulations predict the ultrafast switching observed experimentally and provide new insight into the atomistic mechanisms behind the development and dissolution of stable conducting filaments.

As a second example, I will show the computational design of full density metallic metamaterials with ultra-low stiffness via the stabilization of a negative stiffness state using epitaxy. Key achieving this unprecedented property is a martensitic alloy constrained to a mechanically unstable state by its coherent integration with a compatible, stable second component. Large-scale molecular dynamics simulations confirm the low stiffness expected from the competing response of the two components and provide insight into the mechanisms behind ultra-low stiffness. These novel metamaterials exhibit Young’s moduli over one order of magnitude lower than either constituent, defying long-standing bounds of composite design.

I will also introduce nanoHUB, an open cyberinfrastructure for cloud scientific computing whose goal is to maximize the impact of simulation tools and data. Through nanoHUB developers can make their tools available to the community and educators, students and researchers can run these tools directly from their web-browsers or tablets without downloading or installing any software. With a short tutorial, I will exemplify how nanoHUB is being used in education and research and how its cyberinfrastructure can enhance the impact of simulations in science and engineering.

Alejandro Strachan is a Professor of Materials Engineering at Purdue University and the Deputy Director of the Purdue’s Center for Predictive Materials and Devices (c-PRIMED) and of NSF’s Network for Computational Nanotechnology. Before joining Purdue, he was a Staff Member in the Theoretical Division of Los Alamos National Laboratory and worked as a Postdoctoral Scholar and Scientist at Caltech. He received a Ph.D. in Physics from the University of Buenos Aires, Argentina, in 1999. Among other recognitions, Prof. Strachan was named a Purdue University Faculty Scholar (2012-2017), received the Early Career Faculty Fellow Award from TMS in 2009 and the Schuhmann Best Undergraduate Teacher Award from the School of Materials Engineering, Purdue University in 2007. Prof. Strachan’s research focuses on the development of predictive atomistic and molecular simulation methodologies to describe materials from first principles, their application to problems of technological importance and quantification of associated uncertainties. Application areas of interest include: coupled electronic, chemical and thermo-mechanical processes in devices of interest for nanoelectronics and energy as well as polymers and their composites, molecular solids and active materials, including shape memory and high-energy density materials.

 

Published Sep. 15, 2017 1:12 PM - Last modified Oct. 10, 2017 9:14 AM