Investigation of Dielectric, Ferroelectric, and Strain Responses of (1 - x )[0.90(Bi 0.5 Na 0.5 )TiO 3 - 0.10SrTiO 3 ] - x CuO Ceramics.

The low-temperature sintering of (Bi 0.5 Na 0.5 )TiO 3 -based ceramics can be achieved by sintering aid CuO. Piezoelectric ceramics (1 - x )[0.90(Bi 0.5 Na 0.5 )TiO 3 - 0.10SrTiO 3 ] - x CuO (BNT-ST-Cu) with x = 0, 0.01, 0.02, 0.03, and 0.04 were prepared through the mixed oxide route. A tetragonal structure was indexed for the undoped sample. Its structure was found to be changed to a pseudocubic when Cu was added. For undoped Cu samples, the sintering temperature ( T s ) for sufficient densification was 1160 °C. However, T s was reduced to 1090-1120 °C for Cu-added specimens. Field emission scanning electron microscopy (FE-SEM) showed a uniform and dense grain morphology for all samples. The maximum dielectric constant temperature ( T m ) was decreased with the doping concentration of Cu and applied frequency. The strain was increased with Cu concentration and had the maximum value of 500 pm/V for the sample x = 0.02 with symmetric and slim strain loops.