Size effects on the stabilization and growth of tetragonal ZrO ₂ crystallites in a nanotubular structure

The size effects on the stabilization of ZrO ₂ polymorphs in nanoscale and the growth behavior of their crystallites in 1-D nanotubular structures were investigated. Polycrystalline nanotubular structures of ZrO ₂ with tetragonal nanocrystallites were fabricated using nanoporous polycarbonate (PC) templates and atomic layer deposition (ALD). The as-prepared ZrO ₂ nanotubes showed polycrystalline structures of stabilized tetragonal polymorphs at room temperature. The wall thickness of the ZrO ₂ nanotubes was well controlled by the number of ALD cycles. Faster growth of the tetragonal nanocrystallites was observed in the nanotubes with a 50 nm outer diameter, than those of 200 nm. The Gibbs-Thompson relation can be used to explain the observed nanosize effects on the growth of the tetragonal ZrO ₂ nanocrystallites.