Entropy Model of Nanoregions in Relaxor Ferroelectrics

Abstract

Based on characteristics of polar nanoregions in relaxor ferroelectrics and cooperatively rearranging regions in super-cooled liquid, the identical physics process is considered that the added foreign molecules will restrain the phase transition accompanied with an intermediated state of congregated polar nanoregions. The normal molecules possess tendency to aggregate together below transition temperature. The analyzed result supposes that the polar nanoregions have higher local Curie temperature. The derived results indicate that the temperature dependent change in magnitude of the polar nanoregions causes dielectric dispersion, and applied dc electric field will restrict the change to diminish the dielectric dispersion.

Keywords:

• Relaxor ferroelectrics
• dielectric properties
• domains
• defect

Acknowledgments

This work was supported by Natural Science Foundation (2009CDB027) of Hubei Province, P. R. China.

Communicated by Dr. Deborah J. Taylor