Preparation, Structure, and Electrical Properties of Cobalt-Modified Bi(Sc(3/4)In(1/4))O(3)–PbTiO(3)–Pb(Mg(1/3)Nb(2/3))O(3) High-Temperature Piezoelectric Ceramics

Cobalt-modified 0.40Bi(Sc(3/4)In(1/4))O(3)–0.58PbTiO(3)–0.02Pb(Mg(1/3)Nb(2/3))O(3) ceramics (abbreviated as BSI–PT–PMN–xCo) were produced by conventional two-step solid-state processing. The phase structure, micro structure morphology, and electrical properties of BSI–PT–PMN–xCo 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 B-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 (T(c)) was 412 °C, the piezoelectric constant (d(33)) was 370 pC/N, the remnant polarization (P(r)) was 29.2 μC/cm(2), the relatively dielectric constant (ε(r)) was 1450, the planar electromechanical coupling coefficient (k(p)) was 46.5, and the dielectric loss (tanδ) was 0.051. Together with the enhanced DC resistivity of 10(9) 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.