Potassium Sodium Bismuth Titanate Ceramics: Processing and Property Relationships for Higher-Temperature Electromechanical Actuation

Abstract

The role of potassium content on properties was identified by X-ray powder diffraction, dielectric measurements and field-induced polarization and strain studies. The lowest transition temperature (and subsequently the highest electromechanical activity) was obtained at the morphotropic boundary composition (x = 0.2). Higher potassium contents stabilized the ferroelectric piezoelectric region to higher temperatures. For x = 0.6, the transition temperature increased to 260°C, with a relatively stable d333 = 150--145.10 -12 m/V between 25°C and 200°C. Thus, by tailoring the potassium content, actuator materials could be designed for higher-temperature applications.