A series of sol-gel processed lanthanum modified lead zirconate titanate (PLZT) thin films with La/Zr/Ti ratios of 8.5/65/35, 9/65/35, 9.5/65/35, 15.5/40/60 and 18/30/70 were prepared on indium tin oxide (ITO)-coated Corning 7059 glass substrates and heat-treated at different temperatures from 475℃ to 685℃. The X-ray diffraction and microstructure were investigated. The PLZT thin films of higher Ti/Zr ratio show lower transformation (from pyrochlore to perovskite) temperature and smaller grain sizes.
PLZT(9.5/65/35) thin films were prepared on ITO-coated Corning 7059 glass substrates using a seeding layer [PLZT(15.5/40/60)]. The X-ray diffraction, microstructure, optical transmittance spectra and the polarization vs electric field curves were investigated. The PLZT(9.5/65/35) thin film with the seeding layer shows improved phase content, high optical transmittance and enhanced perovskite transformation kinetics. The grain sizes are reduced (from 5-6 ㎛ to 0.1-0.2 ㎛) and uniform. The fracture surfaces of the films with a seeding layer consist of columnlar structure of which the grains grew from the seeding layer. The optical transmittance is enhanced, and the polarization value at 400KV/cm increases for the film with the seeding layer.
PLZT thin films with La/Zr/Ti ratios of 9.5/65/35, 15.5/40/60 and 18/30/70 were prepared on Corning 7059 glass substrates using a seeding layer [PLZT(14/0/100)]. The X-ray diffraction patterns and the microstructures of the films were investigated. The PLZT(9.5/65/35) thin films without the seeding layer consist of both pyrochlore and amorphous phases. But the PLZT(9.5/65/35) thin films with the seeding layer showed preferred orientation as well as improved perovskite phase content. The orientation of the film was varied with the thickness and the heat-treatment of the seeding layer.
