Sapphire;
Faceting;
High temperature annealing;
Equilibrium state;
INTERNAL CAVITIES;
WULFF SHAPE;
ALUMINA;
SAPPHIRE;
MORPHOLOGY;
ANISOTROPY;
STEPS;
D O I:
10.1016/j.susc.2012.07.024
中图分类号:
O64 [物理化学(理论化学)、化学物理学];
学科分类号:
070304 ;
081704 ;
摘要:
We report on a heat-induced transformation of the surface of a-alumina (0001) crystals which have an off-cut in the [1 (2) over bar 10] direction. Annealing the crystal causes the surface to transform into a regular array of (0001) and (1 (2) over bar 16) facets. The resultant faceted morphology represents the equilibrium state of the system. It is demonstrated that the average terrace periodicity is determined by the annealing temperature. Possible causes for the surface rearrangement are also discussed. This method could be used for producing templates with controlled periodicity for growth of nanostructure arrays. Published by Elsevier B.V.