A Study of the Platinum/Alumina Interface

Single crystal sapphire in one of four orientations (0001), (11 2 0), (1102) and (1010) was bonded to polycrystalline platinum foil at 1330oC under light load 20 N (0.8 MPa) in argon. The different orientations were used as a means to model individual grains within a polycrystal without the uncertain influence of grain boundaries and glass-forming contamination (e.g. SiO2). Partial bonding was observed in all cases. Optical microscopy, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to study the nature of the bond which appears to be physical rather than chemical, in agreement with previous work.