Deposition of PbTiO_3 films on Pt/Si substrates using pulsed laser deposition

摘要

Lead titanate (PbTiO_3) thin films were prepared on platinised silicon substrates by pulsed laser deposition. A predominantly (111) oriented perovskite phase was obtained at a substrate temperature of 530 deg C. Deposition at higher substrate temperatures resulted in the formation of a lead deficient pyrochlore phase PbTi_3O_7. The (111) orientation was slightly enhanced with an increase in the oxygen deposition pressure from 100 mTorr to 150 mTorr. A similar effect was observed with an increase in the post-deposition annealing temperature from 400 deg C to 600 deg C. P-E loops with remanent polarization (P_r) as high as 40 mu C/cm~2 and coercive field E_c = 105 kV/cm were obtained under an electric field of an amplitude of 270 kV/cm at 50 kHz. Impedance spectroscopy and leakage current behaviour of the films are also reported.