Thermal transport properties of MgO and Nd2Zr2O7 pyrochlore by molecular dynamics simulation

Atomic level simulation methods are used to determine the thermal conductivity of magnesium oxide, MgO, and pyrochlore structured neodymium zirconate, Nd2Zr2O7, (NDZ), two potential constituents of inert-matrix fuel systems. A simple anharmonicity analysis correctly predicts that the simulated and experimental values of the thermal conductivity of MgO should be in good agreement, as we explicitly demonstrate. Likewise, they correctly predict significantly that a large correction is needed to bring consistency between the experimental and simulated thermal conductivities for NDZ. Simulations of the thermal conductivity of fine-grained polycrystals of both materials yield estimates of the temperature dependence of the interfacial conductance and of the grain-size dependence of the thermal conductivity.