Citation: M.S. Daw, J.W. Lawson, and C.W. Bauschlicher (2011), "Interatomic potentials for Zirconium Diboride and Hafnium Diboride",
Computational Materials Science,
50(10), 2828-2835. DOI:
10.1016/j.commatsci.2011.04.038.
Abstract: We report on the first interatomic potentials for Zirconium Diboride and Hafnium Diboride. The potentials are of the Tersoff form, and are obtained by fitting to a first-principles database of basic properties of elemental Zr, Hf, B, and the compounds ZrB2 and HfB2. Two variants of the Zr-B potentials have been obtained, and one for Hf-B. The potentials have been tested against a variety of properties of the compound, with the conclusion that they are stable and provide a reasonable representation of the desired properties of the two diborides.
Citation: J.W. Lawson, M.S. Daw, and C.W. Bauschlicher (2011), "Lattice thermal conductivity of ultra high temperature ceramics ZrB
2 and HfB
2 from atomistic simulations",
Journal of Applied Physics,
110(8), 083507. DOI:
10.1063/1.3647754.
Abstract: Atomistic Green-Kubo simulations are performed to evaluate the lattice thermal conductivity for single crystals of the ultra high temperature ceramics ZrB2 and HfB2. Recently developed interatomic potentials are used for these simulations. Heat current correlation functions show rapid oscillations, which can be identified with mixed metal-Boron optical phonon modes. Results for temperatures from 300K to 1000K are presented.
Citation: J.W. Lawson, M.S. Daw, T.H. Squire, and C.W. Bauschlicher (2012), "Computational Modeling of Grain Boundaries in ZrB
2: Implications for Lattice Thermal Conductivity",
Journal of the American Ceramic Society,
95(12), 3971-3978. DOI:
10.1111/jace.12037.
Abstract: A combination of ab initio, atomistic, and finite element methods (FEM) was used to investigate fundamental properties of grain boundaries and grain boundary networks and their impact on lattice thermal conductivity in the ultra high-temperature ceramic ZrB2. The structure, energetics, and lattice thermal conductance of certain low energy grain boundaries were studied. Atomic models of these boundaries were relaxed using density functional theory. Information about bonding across the interfaces was determined from the electron localization function. Interfacial thermal conductances were computed using nonequilibrium molecular dynamics. Microstructural models were used to determine the reduction in lattice thermal conductivity due grain boundary networks where FEM meshes were constructed on top of microstructural images.