Effects of Bi2O3 seeding layer on crystallinity and electrical properties of CSD-derived Bi4−xLaxTi3O12 ferroelectric thin films

The effects of Bi2O3 seeding layer on crystallization temperature, crystallinity and ferroelectric properties of Bi3.35La0.75Ti3O12 (BLT) thin films prepared by chemical solution deposition (CSD) method were investigated. BLT thin films were prepared on Pt/TiOx/SiO2/Si substrates with Bi2O3 seeding layer by a spin-coating technique from metal alkoxide solutions of BLT precursors. BLT gel thin films were calcined at 500 °C for 10 min using rapid thermal annealing (RTA), and then heated at 600–700 °C for 30 min in an O2 atmosphere. Bi2O3 seeding layer was found to be effective to achieve the low-temperature crystallization up to 600 °C and improve the crystallinity and electrical properties of BLT thin films. 650 °C-annealed BLT thin films with the seeding layer showed a high crystallinity with a strong (117) preferred orientation and a dense microstructure with grain sizes of 200–300 nm. They showed a well-saturated P–E hysteresis loop with a Pr of 5.0 μC/cm2 and Ec of 78.8 kV/cm.