Thin Film Materials and the Minimum Thermal Conductivity

点击翻译按钮获取中文摘要

ABSTRACTProposal Number: CTS 9978822Principal Investigator: D. CahillThis award is to support studies of the fundamental scientific issues in heat conduction in thin films by lattice vibrations. Thin films and nanometer-scale multilayers of highly disordered materials will be prepared by magnetron sputtering and characterized by Rutherford backscattering spectroscopy, scanning electron microscopy and x-ray reflectivity. Heat transport in these materials will be quantified using the 3-omega method in the temperature range 35-500 K, and longitudinal speeds of sound will be measured using picosecond ultrasonics. This combination of measurements will facilitate a detailed comparison between the thermal conductivity data and the minimum thermal conductivity model. The objective is to establish a greater understanding of the mechanisms that create high and low thermal conductivities in thin film materials with large disorder. This new knowledge is also expected to expand the range of thin film thermal properties that are available for applications.