Crystallization and dielectrical properties of PLZT films derived from metallo-organic precursors

Lead lanthanum zirconate titanate (PLZT) films were deposited by the metallorganic decomposition (MOD) process using multilayer spinning. The crystallization kinetics, the evolution of the crystallographic structure, the dielectric behavior, and the ferroelectric properties were studied. It was found that a perovskite structure crystallizes from decomposed amorphous precursors in the temperature range 420-570°C. A metastable pyrochlore phase always forms during the crystallization of the films from the amorphous phase, with an activation energy and a frequency factor of 143 kJ/mol and 7.9×10⁹ s^-1 , respectively. Two modifications of the perovskite structure can be obtained for PLZT(8/0/100). One is rhombohedral with a=0.3948 nm and α=89.61° for annealing in air at 550°C; the other is tetragonal with a=0.3909 nm, c=0.4046 nm, and c/a=1.035