Effect of thermal profile on a shift in phase transition temperature of Sb-doped KNN piezoceramic

Abstract

This work investigated the impact of the thermal profile in the shift of phase transition temperature for KNNS piezoceramic, using high-resolution synchrotron x-ray powder diffraction (SXPD) and dielectric measurement. The temperature-dependent dielectric permittivity and SXPD profile showed that all phase transformations occurred at higher temperature under heating than under cooling. Moreover, under cooling from 227 °C to −163 °C and reheating to 227 °C, none of the unit-cell volumes fully recovered to their initial size. These results suggest that the change in unit-cell volume under heating/cooling plays a significant role in the shift of phase transition temperatures that was observed.

Keywords:

• Lead-free piezoceramics
• temperature dependence
• phase transition temperature
• synchrotron x-ray diffraction
• thermal profile

Acknowledgements

We would like to thank Dr.David A.Hall from University of Manchester and Prof.Dr. Chui Tang and Dr. Sarah Day from Diamond Light Source, UK for the access to the Beamline I11 at Diamond Light Source, UK.