Dielectric and Piezoelectric Properties of (Na0.5Bi0.5)(Ti1–xMn x)O3 (x = 0–0.1) Modified Ceramics

We have studied the crystal structure and dielectric and local piezoelectric properties of (Na0.5Bi0.5)(Ti1–xMnx)O3 (x = 0–0.1) modified sodium bismuth titanate-based ceramics and observed the formation of a pseudocubic phase with the perovskite structure. Its unit-cell volume first decreases and then, for x ≥ 0.05, increases. The ceramics undergo phase transitions, which show up as anomalies in their dielectric permittivity near ~450 K and peaks at a Curie temperature of ~600 K. As x increases to 0.04, their Curie temperature decreases by 40 K. The phase transitions near 450 K exhibit well-defined relaxor behavior due to the presence of polar regions in the nonpolar matrix. The samples with x < 0.05 have been shown to have an increased room-temperature dielectric permittivity, which correlates with the increased effective piezoelectric coefficient, suggesting that doping with manganese has an advantageous effect on the functional properties of sodium bismuth titanate ceramics.