Recently, a new family of piezoelectric perovskite materials based on the solid solution (1 - x)BiMeO3-xPbTiO3 (where Me is one or a combination of cations with sum valance +3) have been developed. Specifically, the (1 - x)BiScO3-xPbTiO3 (BS-PT) system is noted for its high Curie temperature (Tc = 450°C) and large piezoelectric coefficient (d33 > 460pC/N). Lanthanum additions, as a donor dopant in the piezoelectric system Pb(Zr,Ti)O3 and other lead based perovskite materials, are commonly utilized to both lower Curie temperature and increase piezoelectric coefficients. In the current work, the effect of lanthanum substitution in the BS-PT system is reported. The results of lanthanum additions in the BS-PT system show no large enhancement of the piezoelectric properties. However, fine grain sized materials (<1μm), desirable for improved mechanical properties, with Curie temperature of 365°C and high piezoelectric coefficient (d33 = 465 pC/N) were successfully produced. The results of this study suggest that for low lanthanum additions, <5 mol%, internal compensation mechanisms in the BS-PT system dominate piezoelectric performance. Further grain size effects in lanthanum doped BS-PT compositions provide the first experimental evidence of significant extrinsic contributions to the piezoelectric properties in this system.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)