  Sol gel obtained YZS (Yttria Stabilized Zirconia) nanocrystals have different
morphologies when they grow on an $\alpha$-alumina substrate after thermal
treatment. When the substrate has planar defects, the nanocrystals grow in
height and are narrow with a crystallographic orientation [111] in the vertical
direction, while when the substrate is a perfect plane at the nanometric scale,
the nanocrystals are rather extended over the substrate and do not grow in
height, with a crystallo- graphic orientation [100] in the vertical direction.
We present here a Monte Carlo approach which computes the actions of the
substrate on the nanocrystals during thermal treatment: one action is the
change in crystallographic orientation depending on the presence of defects and
the other is the action on the morphology of the nanocrystals. The equivalent
of thermal treatment is obtained after applying the Metropolis algorithm with
adequate expressions of the energy depending on the inter-plane spacings and
surface diffusion. Our numerical approach is in good agreement with the
experimental results on the orientations and morphologies of the YSZ
nanocrystals growing on a $\alpha$-alumina substrate with planar defects

Materials Science