Atomistic Modeling of Emerging Materials: From Computational Design to Processing Simulation
Research Laboratory of Electronics
Massachusetts Institute of Technology
12 PM, Friday, February 17th, 2017
1131 Kemper Hall (CE Conference Room)
Abstract: Atom-based modeling is becoming increasingly important for the fundamental understanding and development of new materials. Modern first-principles methods such as density functional theory (DFT) have reached a level of maturity such that the structural, thermodynamic, and functional properties of a wide range of materials can now be predicted in silico with high accuracy. On the other hand, the classical molecular dynamics method, although tending to have less predictive power, enables the direct modeling of the dynamical atomic-level structural evolution of a system at much larger time and length scales than presently possible with quantum mechanics-based methods. In addition, Monte Carlo simulation allows efficient sampling of configuration phase space to predict the statistical properties of a system.
Using my past and present work as examples, this talk aims to illustrate the complementary nature of different atomistic simulation methods, and that they can be rather useful toward the development of novel materials and processing techniques. In the first part of the talk, I will present how first-principles thermodynamic and kinetic analysis leads to the prediction of ferroelastic two-dimensional (2D) materials based on transition metal dichalcogenide monolayers, which has the potential to be ultrathin shape memory materials. The second part of the talk will demonstrate how combined first-principles and Monte Carlo simulations lead to a design strategy for realizing high-temperature ferromagnetic and half-metallic 2D metal-organic frameworks, which have potential for spintronic applications. In the last part of the talk, I will present how combined hydrostatic and deviatoric stresses result in the ordered sintering of ligand-passivated nanoparticle super-crystals into nanowire arrays, as revealed by large-scale molecular dynamics simulations. The insights gained from the simulations are critical to the development of a new low-cost, stress-enabled method for processing nanostructured materials. In all these examples, an additional theme of theory-experiment collaboration as an effective strategy to accelerate material innovation emerges.
Biography: Wenbin Li received his Ph.D. degree in Materials Science and Engineering, with a minor in condensed matter physics, from Massachusetts Institute of Technology in 2015. His doctoral work focused on using large tensorial strain to engineer the internal structure and properties of materials. He was part of the multi-institute collaboration team winning the 2016 R&D Magazine’s R&D 100 award, for “Stress-induced Fabrication of Functionally Designed Nanomaterials”. Currently, he is a postdoctoral associate within the Research Laboratory of Electronics at MIT, where he mainly works on modeling and design of two-dimensional materials for electronics applications.