Research of the Mechanism of Ferroelectric Phase Transition in Perovskite: Empty Orbital Model

Abstract:

The empty orbital model in perovskite ATiO₃-type (A=Mg, Ca, Sr and Ba) ferroelectrics with oxygen octahedra has been proposed. In this study, the impact of temperature on the bond energy of Ti-O has been discussed from the point of view of statistical thermodynamics, then the temperature dependence of equilibrium position of Ti ion has been calculated. The results show that because of the existence of empty orbital, with temperatrue decreasing the repulsion energy of Ti and O ions reduces and the Ti ion shift the equilibrium position in the cooling through the Curie temperature owing to Coulomb interaction. Ferroelectric phase transition in perovskite are successfully explained. Theoretical and experimental results for perovskite ATiO₃-type ferroelectrics are compared and discussed.

• Periodical: Applied Mechanics and Materials (Volumes 130-134)
• Pages: 2809-2812
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.130-134.2809
• Online since: October 2011
• Authors: Chao Fang, Liang Yan Chen
• Keywords: Binding Energy, Ferroelectric, Oxygen Octahedra, Perovskite

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