On the preparation of PLZT thin films grown by pulsed laser deposition

Polycrystalline PLZT thin films have been grown onto glass slides substrate, from a sintered stoichiometric 9/65/35 commercial target, by using a Nd:YAG laser (1064 nm, 7 ns, 10 Hz). The substrate temperature and oxygen pressure were varied during the deposition, as was the post-deposition annealing temperature in order to achieve stoichiometric films with a perovskite structure and with a composition near the ratio 9/65/35. Perovskite PLZT is formed around the substrate temperature of 500 degrees C and oxygen pressure of similar to 0.5 mbar after annealing at 580 degrees C during 90 min. The pyrochlore structure, on the other hand, is always formed in the films during the deposition. However, this structure disappear for annealing temperatures above 550 degrees C; for the films grown at oxygen pressure in the range 0.5-1 mbar and temperature deposition above 450 degrees C. The degree of crystallinity and the structure present in the films is correlated with the deposition conditions. The influence of post-deposition annealing conditions on the formation of perovskite PLZT structure and optical transparency of the films is also discussed. (C) 1998 Elsevier Science Ltd. All rights reserved.