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Multi-paradigm Computational Approaches In Analysis and Design of Energy Harvesting and Storage Materials

August 27, 2014 4:00PM to 5:00PM
Presenter 
Tahir Cagin, Texas A&M University
Location 
Building 440, Room A105-106
Type 
Colloquium
Series 
NST Nanoscience Colloquium
Abstract:
Based on various levels of theory we utilize different computational paradigms to analyze and assess the efficiency and utility of different materials and materials systems both in 3-d bulk and lower dimensional nano structures. As it deems to use we employ initio quantum chemistry, density functional theory, molecular mechanics, molecular dynamics, molecular dynamics simulations, as well as engineering level methods to determine relevant properties (both static and dynamic), relevant coupling coefficients for energy conversion to assess the figure of merit.

In this talk we present this multiparadigm approach as they are applied to thermoelectrics, piezoelectrics, and H-storage materials: For thermoelectrics, we determine the properties such as: Seebeck coefficient, electronic conductivity and thermal conductivities of materials to assess their feasibility as cooling and power generation applications. The efficiency for both applications of thermoelectric materials is slowly increasing function of the figure of merit (ZT), which is a function of these particular transport properties. In this talk, we will present the underlying theory and computational approaches used in determining these properties and discuss applications on bulk and low dimensional nanostructured materials.

The examples include commonly used Bi2Te3, Sb2Te3, their super-lattices; pure-SrTiO3, doped-SrTiO3 and SrTiO3 based perovskite alloys; various ternary and quaternary alloys 1-D and 2-D nanostructures such as C and BN nanotubes and graphene and nano-ribbons. For piezo-electrics, using ab initio DFT, 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.