A phenomenological thermodynamic potential in form of an eight-order polynomial of the Landau-Ginsburg-Devonshire (LGD) expansion has been determined for a bulk potassium niobate (KNbO3) single crystal. Such potential is tested by calculating the structural and ferroelectric properties including polarizations, dielectric constants, lattice constants, and phase transition temperatures as well as their shifts under the hydrostatic pressure. The fitted LGD energy expansion coefficients can be used in the phase-field model to explain and predict ferroelectric properties of the bulk and thin film KNbO3.
Revised: August 27, 2009 |
Published: February 20, 2009
Citation
Liang L., Y. Li, L. Chen, S.Y. Hu, and G. Lu. 2009.A phenomenological thermodynamic potential for potassium niobate.Applied Physics Letters 94, no. 7:Article Number: 072904.PNNL-SA-64607.