|M.Sc Student||Meltzman Hila|
|Subject||Energy and Morphology of Solid-Solid Au-Sapphire Interfaces|
|Department||Department of Materials Science and Engineering||Supervisor||Professor Wayne D. Kaplan|
The measurement of metal-ceramic interface energy is important to understand adhesion and segregation, as well as for the evaluation of mechanical properties. Unlike solid-liquid interfaces, solid-solid interface energy measurements are difficult to perform since they require high-resolution geometrical analysis of the morphology of a single crystalline particle equilibrated on a solid substrate of a dissimilar material. The purpose of this work is to develop a method to measure solid-solid interface energy for metal-ceramic systems. Equilibrated sub-micron Au particles on (0001) and (10-10) surfaces of sapphire, formed by dewetting thin Au films, were chosen as a model system.
The preferred orientation of the solid drops with respect to the substrate was determined by electron backscattered diffraction (EBSD) and X-ray diffraction. Serial sectioning of the Au particles with a known orientation was conducted using a dual-beam focused ion beam (FIB). Facet morphology below the resolution limit of scanning electron microscopy (SEM) was investigated using scanning/transmission electron microscopy (S/TEM) from the center of a sub-micron Au particles, prepared using the FIB “lift-out” technique. This morphological analysis enabled the determination of the interface energy and thermodynamic work of adhesion of a Au-sapphire interface with a known orientation relationship.