The site engineering approach based on site-selective substitutions was utilized to improve the ferroelectric properties in Bi 4Ti 3O 12 thin film. Thin films of (Bi 4-xNd x)(Ti 3-yV y)O 12 with both A- and B-sites substitutions were deposited on (111)Pt/Ti/SiO 2/Si substrates at 600°C by metalorganic chemical vapor deposition. Although the films substituted for the A site by Nd, (Bi 4-xNd x)Ti 3O 12, showed no significant improvement in ferroelectricity, additional substitution for the B site by V contributed to a large ferroelectricity. Superior properties compared to (Bi 4-xLa x)(Ti 3-yV y)O 12 were confirmed for (Bi 4-xNd x)(Ti 3-yV y)O 12 films. We also showed orientation control using Ru-based substrates. (104)-preferred orientation was obtained on (111)Pt/Ti/SiO 2/Si substrates, while (110) and (111) orientations with an advantage for large polarization were stabilized on (001)Ru/SiO 2/Si substrates and actually a larger ferroelectricity was obtained; the remanent polarization (2P r) and coercive field (2E c) of the (Bi 3.35Nd 0.65)(Ti 2.87V 0.13)O 12 film were 34 μC/cm 2 and 290 kV/cm, respectively. No fatigue phenomenon was also observed for the (Bi 3.35Nd 0.65)(Ti 2.87V 0.13)O 12 film up to 10 9 switching cycles.
ASJC Scopus subject areas
- Physics and Astronomy(all)