Influence of strains and defects on ferroelectric and dielectric properties of thin-film barium-strontium titanates
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Data
2002-11-01
Autores
Balzar, D.
Ramakrishnan, P. A.
Spagnol, P.
Mani, S.
Hermann, A. M.
Matin, M. A.
Título da Revista
ISSN da Revista
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Editor
Japan Soc Applied Physics
Resumo
Pristine, W and Mn 1% doped Ba(0.6)Sr(0.4)TiO(3) epitaxial thin films grown on the LaAlO(3) 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 elastic strains and defect-related inhomogeneous strains-by analyzing diffraction line shifts and line broadening, respectively. We found that both elastic and inhomogeneous strains 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 the Landau-Ginzburg-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 defect-related inhomogeneous strain had to be introduced to fully explain the measurements.
Descrição
Palavras-chave
ferroelectric thin films, strain, defects, Curie-Weiss temperature, barium-strontium titanate
Como citar
Japanese Journal of Applied Physics Part 1-regular Papers Brief Communications & Review Papers. Tokyo: Japan Soc Applied Physics, v. 41, n. 11B, p. 6628-6632, 2002.