A validation of a molecular dynamics simulation in determining the thermal conductivity of a La-Zr pyrochlore

Abstract

Semiconductors continue to shrink in size and are now nearing the performance limits of some traditional materials. Silicon Dioxide, which has been used extensively as a gate insulator in MOSFETs, is one such material and so research is focusing on finding a suitable replacement with a high dielectric constant. Oxides of Lanthanum and Zirconium have been identified as possible successors, but these compounds have not been well studied. This thesis is the first step in an attempt to learn more about the thermo-physical and electronic properties of a Lanthanum Zirconium Pyrochlore. A classical molecular dynamics simulation is performed which utilizes a semi-empirical Buckingham interatomic potential to model the van der Waals forces between the atoms in the system. These forces are combined with the electrostatic potential, and the motions of the particles are determined over a corresponding time history. The movement of the energy contained within the atoms is then analyzed using statistical methods to determine the thermal conductivity of the pyrochlore. This conductivity will then be compared with experimental data to determine the validity of the simulation and potential function.