Synthesis and Characterization of a New Ferroelectric with Low Lead Content, a High Curie Temperature, and a High Piezoelectric Response

Abstract

Abstract A new solid solution (1−x)Bi(Fe2/8Ti3/8Mg3/8)O3–(x)PbTiO3 (BFTM‐PT) is synthesized and the electromechanical properties are measured. This system is defined as a low‐lead material with ferroelectric/piezoelectric behavior and a morphotropic phase boundary (MPB) that leads to enhanced properties. The MPB is located between x = 0.30 and 0.35 and coincides with a structural phase transition and a sharp increase in the piezoelectric response. The system demonstrates ferroelectric hysteresis where x = 0.325 displays the best properties with a maximum polarization of 39 µC cm−2 and a remnant polarization of 26 µC cm−2. The range of compositions has high Curie temperature (Tc), ranging from 625–650 °C. Materials with a Tc above 400 °C typically have a low d33 of <50 pC N−1 at room temperature. However, BFTM‐PT has a higher d33 that most other compositions with a Tc in this range, with the highest being 145 pC N−1 for x = 0.375. The d33 drops off above 100 °C, but doping studies can be done in the future to stabilize the piezoelectric response at higher temperatures. These outstanding properties open the possibility of new transducer applications, in particular ones requiring high temperature and high power.

Keywords

• actuators
• electromechanical properties
• ferroelectrics
• piezoelectrics
• sensors