Direct atomic-scale imaging of ceramic interfaces

Abstract

Understanding the atomic structure and chemistry of internal interfaces is often critical to developing interface structure–property relationships. Results are presented from several studies in which Z-contrast scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS) have been employed to solve the atomic structures of oxide interfaces. The Z-contrast imaging technique directly reveals the projected cation sublattices constituting the interface, while EELS provides chemical and local electronic structure information. Because Z-contrast imaging and EELS can be performed simultaneously, direct correlations between structure and chemistry can be made at the atomic scale. The utility of Z-contrast imaging and EELS is demonstrated in three examples: a ZrO 2 24° [100] symmetric tilt grain boundary, a NiO–cubic ZrO 2 eutectic interface and a Ni–cubic ZrO 2 metal–ceramic interface. The power and versatility of Z-contrast and EELS for solving interface structures in oxide systems is clearly demonstrated in these three material systems.