Lead-based perovskites are widely used for actuators, sensors and transducers due to their excellent piezoelectric properties. However, the toxicity of lead for the environment and human health led to focus research efforts on finding substitutes for these materials. One candidate is the Bi_0.5Na_0.5TiO₃-Bi_0.5K_0.5TiO₃ solid solution, due to its interesting properties attributed to the presence of a morphotropic phase boundary in the composition Bi_0.5(Na_0.8K_0.2)_0.5TiO₃. It is known, that the synthesis methods of nanopowders, such as the sol-gel process, allow the control of grain size better that other methods. Consequently, this work focuses on the study of processing conditions and final properties of Bi_0.5(Na_0.8K_0.2)_0.5TiO₃-based ceramics obtained by the sol-gel method.

To obtain the desired phase, the reagents used were sodium acetate (CH₃COONa), potassium acetate (CH₃COOK), bismuth nitrate (Bi(NO₃)₃·5H₂O) and titanium isopropoxide (Ti(OⁱPr)₄).  The acetates and nitrate were dissolved, separately, in glacial acetic acid. Titanium isopropoxide was dissolved in a solution of isopropanol and acetic acid. Acetates and nitrates were added dropwise. The mixture was stirred for one hour. Then, it was dried at 150 °C for 2 hours, and heat-treated at different temperatures (550 to 750 °C). The obtained powders were pressed uniaxially and sintered in the temperature range of 1000