|August 27, 2014
"Multiparadigm Computational Approaches In Analysis and Design of Energy Harvesting and Storage Materials," Tahir Cagin, Texas A&M University, hosted by Alper Kinaci
Abstract: Based on various levels of theory, we use different computational paradigms to analyze and assess the efficiency and utility of different materials and materials systems in both three-dimensional bulk and lower-dimensional nanostructures. We employ initio quantum chemistry, density functional theory (DFT), molecular mechanics, molecular dynamics, and molecular dynamics simulations, as well as engineering level methods to determine relevant properties (both static and dynamic) and relevant coupling coefficients for energy conversion to assess the figure of merit. In this talk, we present this multiparadigm approach as it is applied to thermoelectrics, piezoelectrics, and H-storage materials.
For thermoelectrics, we determine properties such as: Seebeck coefficient, electronic conductivity, and thermal conductivity of materials to assess their feasibility in cooling and power generation applications. The efficiency for both applications of thermoelectric materials is slowly increasing function of the figure of merit, which is a function of these particular transport properties. We will present the underlying theory and computational approaches used in determining these properties and discuss applications for bulk and low-dimensional nanostructured materials. Examples include Bi2Te3, Sb2Te3, and their superlattices; pure-SrTiO3, doped-SrTiO3 and SrTiO3-based perovskite alloys; various ternary and quaternary alloys; and one- and two-dimensional nanostructures such as carbon and BN nanotubes, and graphene and nano-ribbons.
For piezo-electrics, using ab initio DFT and polarizable-charge transfer interaction potentials in molecular dynamics simulations, we determine the piezoelectric coefficients as well as variation of polarization as a function of chemical constitution and nanostructure in ABO3 ceramics.
For H-Storage applications we use molecular dynamics and Grand Canonical Monte Carlo simulations to assess storage capacity of MOFs and CNT-based scaffolds.