Conditioning effects on RTP (Pb,Ca)TiO3 thin films

Calcium modified lead titanate thin films have been spin-coated on Pt/TiO2/ SiO2/(100)Si substrates from sol-gel synthesized solutions containing a 10 mol% excess of PbO. Amorphous layers have been crystallized by a rapid ther mal treatment at 650 degrees C for 50 a, using a heating rate of similar to 30 degrees C/s. Further thermal conditioning treatments were applied to th e films, to study their effects on the ferroelectric response, by means of measurements of hysteresis loops, switching current curves, pyroelectricity , permittivity and leakage current densities. The origin of the leakages in these films is related with the nature of the electrode-ferroelectric inte rfaces. A mechanism based on the redistribution of charged defects after th e thermal conditioning treatments is suggested. These treatments influence the trapping level and lead to the control of pinning of ferroelectric doma ins. This causes a direct effect on the switching process. (C) 1998 Elsevie r Science S.A. All rights reserved.