Preparation, Structure, and Electrical Properties of Cobalt-Modified Bi(ScIn)O-PbTiO-Pb(MgNb)O High-Temperature Piezoelectric Ceramics.

Cobalt-modified 0.40Bi(ScIn)O-0.58PbTiO-0.02Pb(MgNb)O ceramics (abbreviated as BSI-PT-PMN-Co) were produced by conventional two-step solid-state processing. The phase structure, micro structure morphology, and electrical properties of BSI-PT-PMN-Co were systematically studied. The introduction of Co ions exerted a significant influence on the structure and electrical properties. The experiment results demonstrated that Co ions entered the -sites of the lattice, resulting in slight lattice distortion and a smaller lattice constant. The average grain size increased from ~1.94 μm to ~2.68 μm with the increasing Co content. The optimized comprehensive electrical properties were obtained with proper Co-modified content 0.2 wt.%. The Curie temperature () was 412 °C, the piezoelectric constant () was 370 pC/N, the remnant polarization () was 29.2 μC/cm, the relatively dielectric constant () was 1450, the planar electromechanical coupling coefficient () was 46.5, and the dielectric loss (tan) was 0.051. Together with the enhanced DC resistivity of 10 Ω cm under 300 °C and good thermal stability, BSI-PT-PMN-0.2Co ceramic is a promising candidate material for high-temperature piezoelectric applications.