Influence of AlO nanoparticle doping on depolarization temperature, and electrical and energy harvesting properties of lead-free 0.94(BiNa)TiO-0.06BaTiO ceramics.

In this research article, the effects of AlO nanoparticles (0-1.0 mol%) on the phase formation, microstructure, dielectric, ferroelectric, piezoelectric, electric field-induced strain and energy harvesting properties of the 0.94(BiNa)TiO-0.06BaTiO (BNT-6BT) ceramic were investigated. All ceramics have been synthesized by a conventional mixed oxide method. The XRD and Raman spectra showed coexisting rhombohedral and tetragonal phases throughout the entire compositional range. An increase of the grain size, , , and values was noticeable when AlO was added. Depolarization temperature ( ), which was determined by the thermally stimulated depolarization current (TSDC), tended to increase with AlO content. The good ferroelectric properties ( = 32.64 μC cm, = 30.59 kV cm) and large low-field (205 pC N) values were observed for the 0.1 mol% AlO ceramic. The small AlO additive improved the electric field-induced strain ( and ). The 1.0 mol% AlO ceramic had a large piezoelectric voltage coefficient ( = 32.6 × 10 Vm N) and good dielectric properties ( = 6542, = 93 °C, = 108 °C, = 324 °C and = 164 K). The highest off-resonance figure of merit (FoM) for energy harvesting of 6.36 pm N was also observed for the 1.0 mol% AlO ceramic, which is suggesting that this ceramic has potential to be one of the promising lead-free piezoelectric candidates for further use in energy harvesting applications.