Thermodynamics and Ferroelectric Properties of KNbO3

Journal Article · Sun Nov 15 04:00:00 EST 2009 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3260242· OSTI ID:1028095

Liang, Linyun; Li, Yulan; Chen, L Q; Hu, Shenyang Y; Lu, Guang-Hong

The Landau-Ginsburg-Devonshire (LGD) phenomenological theory is employed to model and predict the ferroelectric phase transitions and properties of single-domain potassium niobate (KNbO3). Based on the LGD theory and the experimental data of KNbO3 single crystal, an eighth-order polynomial of free energy function is proposed. The fitted coefficients are validated by comparing to a set of experimental measured values including phase transition temperatures, spontaneous polarization, dielectric constants, and lattice constants. The effects of hydrostatic pressure and external electric field on phase transition temperatures and piezoelectric coefficients are investigated. The free energy function may be used a phase-field modeling to predict ferroelectric domain structures and properties of KNbO3 bulk crystals and films by phase-field approach.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1028095
• Report Number(s): PNNL-SA-69230; AF5831060
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 10 Vol. 106; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DATA
DOMAIN STRUCTURE
ELECTRIC FIELDS
FREE ENERGY
HYDROSTATICS
MONOCRYSTALS
NIOBATES
PERMITTIVITY
POLARIZATION
POLYNOMIALS
POTASSIUM
SIMULATION
THERMODYNAMICS
TRANSITION TEMPERATURE
Thermodynamics
ferroelectric transition
free energy function
potassium niobate (KNbO3)