Influence of Strains and Defects on Ferroelectric and Dielectric Properties of Thin-Film Barium-Strontium Titanates

Published

November 1, 2002

Author(s)

Davor Balzar, P A. Ramakrishnan, P Spangnol, S Mani, A M. Hermann, M A. Matin

Abstract

Pristine, W and Mn 1% doped BaO 6SrO.4TiO3 epitaxial thin films grown on the LaAIO3 substrate were deposited by Pulsed Laser Deposition (PLD). Dielectric and ferroelectric properties were determined by the capacitance measurements and x-ray diffraction was used to determine both residual strains and defect densities by analyzing diffraction line shifts and line broadening, respectively. We found that both elastic strains and defect densities are affected by doping. This strain correlates with the change in Curie-Weiss temperature and can qualitatively explain changes in dielectric loss. To explain the experimental findings, we model the dielectric and ferroelectric properties of interest in the framework of Landau-Ginsburg-Devonshire thermodynamic theory. As expected, an elastic-strain contribution due to the epilayer-substrate misfit has an important influence on the free-energy. However, additional terms that correspond to the inelastic strain component had to be introduced to fully explain the measurements.

Citation

Japanese Journal of Applied Physics Part 1-Regular Papers Brief Communications & Review Papers

Volume

41

Issue

No. 11 B

Pub Type

Journals

Keywords

barium-strontium titanate, Curie-Weiss temperature, defects, ferroelectric thin films, strains

Citation

Balzar, D. , Ramakrishnan, P. , Spangnol, P. , Mani, S. , Hermann, A. and Matin, M. (2002), Influence of Strains and Defects on Ferroelectric and Dielectric Properties of Thin-Film Barium-Strontium Titanates, Japanese Journal of Applied Physics Part 1-Regular Papers Brief Communications & Review Papers (Accessed April 25, 2024)