Rapid biaxial texture development during nucleation of MgO thin films during ion beam-assisted deposition

We propose a mechanism for the nucleation of highly aligned biaxially textured MgO on amorphous Si3N4 during ion beam-assisted deposition. Using transmission electron microscopy, reflection high-energy electron diffraction, energy dispersive x-ray analysis, and ellipsometery, we have observed that highly aligned biaxially textured grains emerge from a "diffraction-amorphous" film when the film thickens from 3.5 to 4.5 nm. Transmission electron microscopy dark-field images also show the onset of rapid grain growth during this same film thickness interval. These results suggest biaxial texturing through aligned solid phase crystallization.