Effect of Electric Field on Hydrostatic Piezoelectric Coefficients of Single Domain PZN-PT Crystals

Abstract

The effect of dc bias electric field on the hydrostatic piezoelectric coefficient d_h in Lead Zinc Niobate-Lead Titanate (PZN:PT) single crystal solid solutions in the vicinity of the morphotropic phase boundary (MPB) is studied. The hydrostatic measurements can be very important to gain insight into these materials. In particular, the discrepancy between sum of piezoelectric coefficients d₃₃+ 2 d₃₁ vs. hydrostatic d_h coefficient measured directly suggests the importance of extrinsic contributions.

Limiting values of measured hydrostatic piezoelectric coefficients d_h for high electric fields are compared with calculated theoretic values from the Landau-Devonshire-Ginzburg (LGD) phenomenological theory.

The influence of complicated microstructure within the single domain region is studied. Such microstructure could possibly account for the inability of the LGD phenomenology to give correct electric field bias dependence of dielectric constant.

Keywords:

• Single crystals
• morphotropic phase boundary
• piezoelectric hydrostatic measurements
• extrinsic contribution

ACKNOWLEDGEMENTS

This work was supported by the Grant Agency of the Czech Republic (Project No. 202/03/0569) and by the Ministry of Education of the Czech Republic (Project MSM 242 200 002). The crystals used for this study were provide by Dr. T. R. Shrout, Dr. S. Zhang and Dr. E. Furman through the Materials Research Institute of the Pennsylvania State University.