Dielectric Nanocomposite Layering Configurations for Thermal Conductivity Reduction

Thermal transport in crystals is governed by dynamic phenomena that take place at the atomic scale, namely phonon dispersion and scattering. A growing understanding of these mechanisms, coupled with increasingly capable nanofabrication and characterization technologies, provide a not-too-distant opportunity for designing a new class of materials with tailored thermal characteristics such as thermal conductivity, among other physical characteristics. Focusing on layered nanocomposites, also known as superlattices, modeled using the Lennard-Jones potential as a starting platform, we examine the effects of layering topology on the bulk property of thermal conductivity. We use molecular dynamics simulations to examine the link between structure and property; and employ ideas from phononic crystal design to investigate the potential of realizing dielectric crystals with exceedingly low thermal conductivities. This work potentially targets a range of applications such as thermal insulators for space applications and thermoelectrics for energy harvesting.