Revisit of Phase Transformation Kinetics in PZT Thin Films by Sol-Gel Method Using Scanning Force Microscopy

Abstract

Transformation kinetics of pyrochlore to perovskite phase in lead zirconate titanate (PZT) thin films have been studied. Sol-gel PZT thin films on platinum electrode were prepared with 50 and 100 nm in thickness. Isothermal annealing was used to study the nucleation and growth kinetics of perovskite phase. Piezo-response force microscopy (PFM), a variant of scanning force microscopy (SFM), provides information on the volume fraction of the transformed phases and size of the grains with higher resolution as well as larger area than other microscopic techniques. The volume fraction of the transformed perovskite phase was taken from the topographical and piezo-response images by SFM and PFM. Avrami's model for the kinetics of transformation was applied to determine Avrami's coefficient (n) and rate constant (k). The effective activation energy of transformation from pyrochore to perovskite was found to be about 220 and 227 kJ/mol for 50 and 100 nm thick PZT films, respectively.

Keywords:

• Transformation
• PZT
• sol-gel
• AFM
• PFM

ACKNOWLEDGEMENTS

The financial support from Kookmin University as an internal research fund for 2004 is gratefully acknowledged.