The Effect of Barium Substitution on the Ferroelectric Properties of Sr2Nb2O7 Ceramics

This work revealed that the solid solution compounds of Sr2xBaxNb2O7 are promising lead-free materials for high-temperature piezoelectric sensor application. These compounds were confirmed as ferroelectric materials with high Curie points (> 900 degrees C) by their piezoelectric activity after poling, ferroelectric domain switching in their PE hysteresis loops and thermal depoling behavior. The effect of Ba substitution on the structure and properties of Sr2xBaxNb2O7 (x<1.0) was investigated. The solid solution limit of Sr2xBaxNb2O7 was determined by XRD as x<0.6. The a-, b-, c- axes, and cell volume increase with Ba addition. The textured ceramics of Sr2xBaxNb2O7 were prepared for the first time. The highest d33 was measured as 3.6 +/- 0.1pC/N for Sr1.8Ba0.2Nb2O7.