We have used aberration corrected in situ transmission electron microscopy to study the interface between liquid Al and different sapphire facet planes, including quantitative analysis of the degree of residual contrast delocalization, ensuring that the experimental contrast perturbations can be associated with density perturbations in the liquid. The results confirm that the liquid is ordered at the interface, and the degree of ordering varies as a function of the sapphire facet planes, with a decreasing degree of order according to (0006) >(1210) >(1012) ≥ (1014).

We present an in situ electron energy loss spectroscopy (EELS) study of ordering of liquid Al at various Al-Al2O3 interfaces. This technique utilizes precise measurements of the shifts in bulk plasmon resonance and their sensitivity to the valence electron density. Plasmon EELS combined with high resolution transmission electron microscopy provides information regarding the chemical composition in liquid Al at Al-Al2O3 interfaces. Preferential oxygen segregation to the (0006) Al2O3 plane was verified, and the (101¯2) Al2O3 plane was found to contain the lowest amount of segregated species.

Microstructural evolution in the near-surface layer of a model metal-ceramic system, Ptimplanted high-purity polycrystalline Al2O3 (PCA), was studied, and compared to that in Ptimplanted sapphire. Interactions between Pt particles and migrating ! /! grain boundaries in PCA caused Pt particle redistribution and Pt loss, and were evaluated in the context of Zenerpinning and particle-drag theories. The experimental method allows the transition from the original to the new equilibrium shape due to the changes in orientation relationship (OR) to be examined. As a result of the potentially wide range of equilibrium shapes, interface crystallographies, and transitional morphologies the microstructural evolution imposes, the experimental method provides a flexible framework for fundamental studies of the energetic and kinetic properties of ceramic-metal interfaces.

The interface between hematite (a-Fe 2 III