Lead-free, piezoelectric (Na,K)NbO3-BaZrO3-(Bi,Li)TiO3 films were epitaxially grown onto (100) SrTiO3 substrate via pulsed laser deposition. The effects of post-annealing temperature on the crystal phases, mosaic spread, and chemical composition of the deposited (Na,K)NbO3 and (Na,K)NbO3-BaZrO3-(Bi,Li)TiO3 films were analyzed. Results indicate the epitaxial growth of (Na,K)NbO3-BaZrO3-(Bi,Li)TiO3 films deposited at an oxygen pressure (PO2) of ≥40 Pa and substrate temperature (Ts) of 800°C. The alkaline-deficiency could be suppressed in the (Na,K)NbO3-BaZrO3-(Bi,Li)TiO3 films deposited at PO2 ≥ 70 Pa. AFM profile of the (Na,K)NbO3 post-annealed at 1000°C indicates the epitaxial growth of film with atomically flat step-terrace structure, while that of the (Na,K)NbO3-BaZrO3-(Bi,Li)TiO3 film post-annealed at 1200°C shows relatively smooth surface with step-terrace structure and several cubic crystals. It was also found that the preferential evaporation of alkaline components could be suppressed by annealing under covered substrate condition.
- laser ablation