Control of morphology and orientation of grains in chemical-solution-deposited Bi3.15Nd0.85Ti3O12 thin films

Bi3.15Nd0.85Ti3O12 thin films were obtained on Pt/Ti/SiO2/Si by the chemical solution deposition method. The influence of the annealing temperature and the heat treatment approach on the grain morphology and orientation of the films and their ferroelectric properties were investigated. It is shown that films annealed at 650 °C display microstructure with fine grains; those annealed at 750 °C have the columnar grain morphology if the rapid thermal annealing is adopted, but both columnar and fine grains are observed when the conventional thermal annealing is adopted. A competition between the nucleation and grain growth exists in determining the grain orientation, and the dominator varies depending on the annealing condition. The ferroelectric properties mainly depend on their grain orientation, but are also affected by the grain size.